[Micronaut] Receiving Japanese(Shift-JIS) data as HTTPResponse

Intro

I will try using Japanese(Shift-JIS) text data in my Micronaut application in this time.

Change default file encoding

By default, the encoding for my Micronaut application is “windows-31j”.
When I use Japanese in the comment, an exception will occur, so I should change the encoding to UTF-8.

build.gradle.kts

<span>..</span><span>.</span>
<span>tasks</span><span>.</span><span>withType</span><span><</span><span>JavaCompile</span><span>>().</span><span>configureEach</span> <span>{</span>
    <span>options</span><span>.</span><span>encoding</span> <span>=</span> <span>"UTF-8"</span>
<span>}</span>
<span>..</span><span>.</span>
<span>tasks</span><span>.</span><span>withType</span><span><</span><span>JavaCompile</span><span>>().</span><span>configureEach</span> <span>{</span>
    <span>options</span><span>.</span><span>encoding</span> <span>=</span> <span>"UTF-8"</span>
<span>}</span>
...
tasks.withType<JavaCompile>().configureEach {
    options.encoding = "UTF-8"
}

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• Gradleでコンパイル時の文字コードを指定する(Kotlin DSL版) – kdnakt blog
• Understanding Tasks – Gradle

Setting HTTPResponse encoding

I can use specific encoding for HTTPResponse like below.

HomeController.java

<span>package</span> <span>jp.masanori.responsesample</span><span>;</span>
<span>import</span> <span>io.micronaut.http.HttpResponse</span><span>;</span>
<span>import</span> <span>io.micronaut.http.MutableHttpResponse</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Controller</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Get</span><span>;</span>
<span>@Controller</span><span>(</span><span>"/sample"</span><span>)</span>
<span>public</span> <span>class</span> <span>HomeController</span> <span>{</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/utf8"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=utf-8"</span><span>)</span>
    <span>public</span> <span>MutableHttpResponse</span><span><</span><span>String</span><span>></span> <span>getUtf8</span><span>(){</span>        
        <span>return</span> <span>HttpResponse</span><span>.</span><span>ok</span><span>(</span><span>"こんにちは"</span><span>);</span>
    <span>}</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/shiftjis"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=Shift_JIS"</span><span>)</span>
    <span>public</span> <span>String</span> <span>getShiftjis</span><span>(){</span>
        <span>return</span> <span>"こんにちは"</span><span>;</span>
    <span>}</span>
<span>}</span>
<span>package</span> <span>jp.masanori.responsesample</span><span>;</span>

<span>import</span> <span>io.micronaut.http.HttpResponse</span><span>;</span>
<span>import</span> <span>io.micronaut.http.MutableHttpResponse</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Controller</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Get</span><span>;</span>

<span>@Controller</span><span>(</span><span>"/sample"</span><span>)</span>
<span>public</span> <span>class</span> <span>HomeController</span> <span>{</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/utf8"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=utf-8"</span><span>)</span>
    <span>public</span> <span>MutableHttpResponse</span><span><</span><span>String</span><span>></span> <span>getUtf8</span><span>(){</span>        
        <span>return</span> <span>HttpResponse</span><span>.</span><span>ok</span><span>(</span><span>"こんにちは"</span><span>);</span>
    <span>}</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/shiftjis"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=Shift_JIS"</span><span>)</span>
    <span>public</span> <span>String</span> <span>getShiftjis</span><span>(){</span>
        <span>return</span> <span>"こんにちは"</span><span>;</span>
    <span>}</span>
<span>}</span>
package jp.masanori.responsesample;

import io.micronaut.http.HttpResponse;
import io.micronaut.http.MutableHttpResponse;
import io.micronaut.http.annotation.Controller;
import io.micronaut.http.annotation.Get;

@Controller("/sample")
public class HomeController {
    @Get(uri="/utf8", produces = "text/plain;charset=utf-8")
    public MutableHttpResponse<String> getUtf8(){        
        return HttpResponse.ok("こんにちは");
    }
    @Get(uri="/shiftjis", produces = "text/plain;charset=Shift_JIS")
    public String getShiftjis(){
        return "こんにちは";
    }
}

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Receiving Shift-JIS strings as HTTPResponse by HttpClient

I can receive them by HttpClient like below.

FileController.java

<span>package</span> <span>jp.masanori.websample</span><span>;</span>
<span>import</span> <span>java.io.File</span><span>;</span>
<span>import</span> <span>java.io.IOException</span><span>;</span>
<span>import</span> <span>java.nio.file.Files</span><span>;</span>
<span>import</span> <span>java.io.InputStreamReader</span><span>;</span>
<span>import</span> <span>java.io.ByteArrayInputStream</span><span>;</span>
<span>import</span> <span>java.io.BufferedReader</span><span>;</span>
<span>import</span> <span>com.fasterxml.jackson.core.JsonProcessingException</span><span>;</span>
<span>import</span> <span>com.fasterxml.jackson.databind.ObjectMapper</span><span>;</span>
<span>import</span> <span>io.micronaut.core.io.buffer.ByteBuffer</span><span>;</span>
<span>import</span> <span>io.micronaut.http.HttpHeaders</span><span>;</span>
<span>import</span> <span>io.micronaut.http.HttpRequest</span><span>;</span>
<span>import</span> <span>io.micronaut.http.HttpResponse</span><span>;</span>
<span>import</span> <span>io.micronaut.http.HttpStatus</span><span>;</span>
<span>import</span> <span>io.micronaut.http.MediaType</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Controller</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Get</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Part</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Post</span><span>;</span>
<span>import</span> <span>io.micronaut.http.client.HttpClient</span><span>;</span>
<span>import</span> <span>io.micronaut.http.multipart.CompletedFileUpload</span><span>;</span>
<span>import</span> <span>jp.masanori.dto.ComputeResult</span><span>;</span>
<span>import</span> <span>jp.masanori.dto.ComputingStatusRequest</span><span>;</span>
<span>import</span> <span>reactor.core.publisher.Mono</span><span>;</span>
<span>@Controller</span><span>(</span><span>"/files"</span><span>)</span>
<span>public</span> <span>class</span> <span>FileController</span> <span>{</span>
    <span>private</span> <span>final</span> <span>HttpClient</span> <span>httpClient</span><span>;</span>
    <span>public</span> <span>FileController</span><span>(</span><span>HttpClient</span> <span>httpClient</span><span>)</span> <span>{</span>
        <span>this</span><span>.</span><span>httpClient</span> <span>=</span> <span>httpClient</span><span>;</span>
    <span>}</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/message"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=utf-8"</span><span>)</span>
    <span>public</span> <span>Mono</span><span><</span><span>String</span><span>></span> <span>getShiftJisText</span><span>()</span> <span>throws</span> <span>IOException</span> <span>{</span>
        <span>HttpRequest</span><span><?></span> <span>req</span> <span>=</span> <span>HttpRequest</span><span>.</span><span>GET</span><span>(</span><span>"http://localhost:8085/sample/shiftjis"</span><span>);</span>
        <span>return</span> <span>Mono</span><span>.</span><span>from</span><span>(</span><span>httpClient</span><span>.</span><span>retrieve</span><span>(</span><span>req</span><span>));</span>
    <span>}</span>
<span>}</span>
<span>package</span> <span>jp.masanori.websample</span><span>;</span>

<span>import</span> <span>java.io.File</span><span>;</span>
<span>import</span> <span>java.io.IOException</span><span>;</span>
<span>import</span> <span>java.nio.file.Files</span><span>;</span>
<span>import</span> <span>java.io.InputStreamReader</span><span>;</span>
<span>import</span> <span>java.io.ByteArrayInputStream</span><span>;</span>
<span>import</span> <span>java.io.BufferedReader</span><span>;</span>

<span>import</span> <span>com.fasterxml.jackson.core.JsonProcessingException</span><span>;</span>
<span>import</span> <span>com.fasterxml.jackson.databind.ObjectMapper</span><span>;</span>

<span>import</span> <span>io.micronaut.core.io.buffer.ByteBuffer</span><span>;</span>
<span>import</span> <span>io.micronaut.http.HttpHeaders</span><span>;</span>
<span>import</span> <span>io.micronaut.http.HttpRequest</span><span>;</span>
<span>import</span> <span>io.micronaut.http.HttpResponse</span><span>;</span>
<span>import</span> <span>io.micronaut.http.HttpStatus</span><span>;</span>
<span>import</span> <span>io.micronaut.http.MediaType</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Controller</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Get</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Part</span><span>;</span>
<span>import</span> <span>io.micronaut.http.annotation.Post</span><span>;</span>
<span>import</span> <span>io.micronaut.http.client.HttpClient</span><span>;</span>
<span>import</span> <span>io.micronaut.http.multipart.CompletedFileUpload</span><span>;</span>
<span>import</span> <span>jp.masanori.dto.ComputeResult</span><span>;</span>
<span>import</span> <span>jp.masanori.dto.ComputingStatusRequest</span><span>;</span>
<span>import</span> <span>reactor.core.publisher.Mono</span><span>;</span>

<span>@Controller</span><span>(</span><span>"/files"</span><span>)</span>
<span>public</span> <span>class</span> <span>FileController</span> <span>{</span>
    <span>private</span> <span>final</span> <span>HttpClient</span> <span>httpClient</span><span>;</span>
    <span>public</span> <span>FileController</span><span>(</span><span>HttpClient</span> <span>httpClient</span><span>)</span> <span>{</span>
        <span>this</span><span>.</span><span>httpClient</span> <span>=</span> <span>httpClient</span><span>;</span>
    <span>}</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/message"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=utf-8"</span><span>)</span>
    <span>public</span> <span>Mono</span><span><</span><span>String</span><span>></span> <span>getShiftJisText</span><span>()</span> <span>throws</span> <span>IOException</span> <span>{</span>

        <span>HttpRequest</span><span><?></span> <span>req</span> <span>=</span> <span>HttpRequest</span><span>.</span><span>GET</span><span>(</span><span>"http://localhost:8085/sample/shiftjis"</span><span>);</span>
        <span>return</span> <span>Mono</span><span>.</span><span>from</span><span>(</span><span>httpClient</span><span>.</span><span>retrieve</span><span>(</span><span>req</span><span>));</span>
    <span>}</span>
<span>}</span>
package jp.masanori.websample;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.io.InputStreamReader;
import java.io.ByteArrayInputStream;
import java.io.BufferedReader;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import io.micronaut.core.io.buffer.ByteBuffer;
import io.micronaut.http.HttpHeaders;
import io.micronaut.http.HttpRequest;
import io.micronaut.http.HttpResponse;
import io.micronaut.http.HttpStatus;
import io.micronaut.http.MediaType;
import io.micronaut.http.annotation.Controller;
import io.micronaut.http.annotation.Get;
import io.micronaut.http.annotation.Part;
import io.micronaut.http.annotation.Post;
import io.micronaut.http.client.HttpClient;
import io.micronaut.http.multipart.CompletedFileUpload;
import jp.masanori.dto.ComputeResult;
import jp.masanori.dto.ComputingStatusRequest;
import reactor.core.publisher.Mono;

@Controller("/files")
public class FileController {
    private final HttpClient httpClient;
    public FileController(HttpClient httpClient) {
        this.httpClient = httpClient;
    }
    @Get(uri="/message", produces = "text/plain;charset=utf-8")
    public Mono<String> getShiftJisText() throws IOException {

        HttpRequest<?> req = HttpRequest.GET("http://localhost:8085/sample/shiftjis");
        return Mono.from(httpClient.retrieve(req));
    }
}

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But when I receive a Shift-JIS encoded file, the values will be garbled.

sample.txt

こんにちは
こんにちは
こんにちは

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FileController.java

<span>...</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/message"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=utf-8"</span><span>)</span>
    <span>public</span> <span>Mono</span><span><</span><span>String</span><span>></span> <span>getShiftJisText</span><span>()</span> <span>throws</span> <span>IOException</span> <span>{</span>
        <span>HttpRequest</span><span><?></span> <span>req</span> <span>=</span> <span>HttpRequest</span><span>.</span><span>GET</span><span>(</span><span>"http://localhost:8085/sample.txt"</span><span>);</span>
        <span>return</span> <span>Mono</span><span>.</span><span>from</span><span>(</span><span>httpClient</span><span>.</span><span>retrieve</span><span>(</span><span>req</span><span>));</span>
    <span>}</span>
<span>...</span>
<span>...</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/message"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=utf-8"</span><span>)</span>
    <span>public</span> <span>Mono</span><span><</span><span>String</span><span>></span> <span>getShiftJisText</span><span>()</span> <span>throws</span> <span>IOException</span> <span>{</span>

        <span>HttpRequest</span><span><?></span> <span>req</span> <span>=</span> <span>HttpRequest</span><span>.</span><span>GET</span><span>(</span><span>"http://localhost:8085/sample.txt"</span><span>);</span>
        <span>return</span> <span>Mono</span><span>.</span><span>from</span><span>(</span><span>httpClient</span><span>.</span><span>retrieve</span><span>(</span><span>req</span><span>));</span>
    <span>}</span>
<span>...</span>
...
    @Get(uri="/message", produces = "text/plain;charset=utf-8")
    public Mono<String> getShiftJisText() throws IOException {

        HttpRequest<?> req = HttpRequest.GET("http://localhost:8085/sample.txt");
        return Mono.from(httpClient.retrieve(req));
    }
...

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Result

����ɂ���
����ɂ���
����ɂ���

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To prevent this, I should set the encoding to receive data.

<span>...</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/message"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=utf-8"</span><span>)</span>
    <span>public</span> <span>Mono</span><span><</span><span>String</span><span>></span> <span>getShiftJisText</span><span>()</span> <span>throws</span> <span>IOException</span> <span>{</span>
        <span>HttpRequest</span><span><?></span> <span>req</span> <span>=</span> <span>HttpRequest</span><span>.</span><span>GET</span><span>(</span><span>"http://localhost:8085/sample.txt"</span><span>)</span>
            <span>.</span><span>contentType</span><span>(</span><span>MediaType</span><span>.</span><span>TEXT_JSON_TYPE</span><span>);</span>
        <span>// receiving data as ByteBuffer</span>
        <span>HttpResponse</span><span><</span><span>ByteBuffer</span><span>></span> <span>res</span> <span>=</span> <span>Mono</span><span>.</span><span>from</span><span>(</span><span>httpClient</span><span>.</span><span>exchange</span><span>(</span><span>req</span><span>,</span> <span>ByteBuffer</span><span>.</span><span>class</span><span>)).</span><span>block</span><span>();</span>
        <span>if</span><span>(</span><span>res</span><span>.</span><span>status</span><span>()</span> <span>!=</span> <span>HttpStatus</span><span>.</span><span>OK</span><span>)</span> <span>{</span>
            <span>return</span> <span>Mono</span><span>.</span><span>empty</span><span>();</span>
        <span>}</span>
        <span>// set encoding and read data</span>
        <span>try</span><span>(</span><span>ByteArrayInputStream</span> <span>input</span> <span>=</span> <span>new</span> <span>ByteArrayInputStream</span><span>(</span><span>res</span><span>.</span><span>body</span><span>().</span><span>toByteArray</span><span>());</span>
            <span>BufferedReader</span> <span>br</span> <span>=</span> <span>new</span> <span>BufferedReader</span><span>(</span><span>new</span> <span>InputStreamReader</span><span>(</span><span>input</span><span>,</span> <span>"SJIS"</span><span>)))</span> <span>{</span>            
            <span>String</span> <span>line</span> <span>=</span> <span>""</span><span>;</span>
            <span>StringBuilder</span> <span>result</span> <span>=</span> <span>new</span> <span>StringBuilder</span><span>();</span>
            <span>while</span><span>((</span><span>line</span> <span>=</span> <span>br</span><span>.</span><span>readLine</span><span>())</span> <span>!=</span> <span>null</span><span>)</span> <span>{</span>
                <span>result</span><span>.</span><span>append</span><span>(</span><span>String</span><span>.</span><span>format</span><span>(</span><span>"%s%s"</span><span>,</span> <span>line</span><span>,</span> <span>"\r\n"</span><span>));</span>
            <span>}</span>
            <span>return</span> <span>Mono</span><span>.</span><span>just</span><span>(</span><span>result</span><span>.</span><span>toString</span><span>());</span>
        <span>}</span><span>catch</span><span>(</span><span>IOException</span> <span>e</span><span>)</span> <span>{</span>
        <span>}</span>
        <span>return</span> <span>Mono</span><span>.</span><span>empty</span><span>();</span>
    <span>}</span>
<span>...</span>
<span>...</span>
    <span>@Get</span><span>(</span><span>uri</span><span>=</span><span>"/message"</span><span>,</span> <span>produces</span> <span>=</span> <span>"text/plain;charset=utf-8"</span><span>)</span>
    <span>public</span> <span>Mono</span><span><</span><span>String</span><span>></span> <span>getShiftJisText</span><span>()</span> <span>throws</span> <span>IOException</span> <span>{</span>
        <span>HttpRequest</span><span><?></span> <span>req</span> <span>=</span> <span>HttpRequest</span><span>.</span><span>GET</span><span>(</span><span>"http://localhost:8085/sample.txt"</span><span>)</span>
            <span>.</span><span>contentType</span><span>(</span><span>MediaType</span><span>.</span><span>TEXT_JSON_TYPE</span><span>);</span>
        <span>// receiving data as ByteBuffer</span>
        <span>HttpResponse</span><span><</span><span>ByteBuffer</span><span>></span> <span>res</span> <span>=</span> <span>Mono</span><span>.</span><span>from</span><span>(</span><span>httpClient</span><span>.</span><span>exchange</span><span>(</span><span>req</span><span>,</span> <span>ByteBuffer</span><span>.</span><span>class</span><span>)).</span><span>block</span><span>();</span>
        <span>if</span><span>(</span><span>res</span><span>.</span><span>status</span><span>()</span> <span>!=</span> <span>HttpStatus</span><span>.</span><span>OK</span><span>)</span> <span>{</span>
            <span>return</span> <span>Mono</span><span>.</span><span>empty</span><span>();</span>
        <span>}</span>
        <span>// set encoding and read data</span>
        <span>try</span><span>(</span><span>ByteArrayInputStream</span> <span>input</span> <span>=</span> <span>new</span> <span>ByteArrayInputStream</span><span>(</span><span>res</span><span>.</span><span>body</span><span>().</span><span>toByteArray</span><span>());</span>
            <span>BufferedReader</span> <span>br</span> <span>=</span> <span>new</span> <span>BufferedReader</span><span>(</span><span>new</span> <span>InputStreamReader</span><span>(</span><span>input</span><span>,</span> <span>"SJIS"</span><span>)))</span> <span>{</span>            
            <span>String</span> <span>line</span> <span>=</span> <span>""</span><span>;</span>
            <span>StringBuilder</span> <span>result</span> <span>=</span> <span>new</span> <span>StringBuilder</span><span>();</span>
            <span>while</span><span>((</span><span>line</span> <span>=</span> <span>br</span><span>.</span><span>readLine</span><span>())</span> <span>!=</span> <span>null</span><span>)</span> <span>{</span>
                <span>result</span><span>.</span><span>append</span><span>(</span><span>String</span><span>.</span><span>format</span><span>(</span><span>"%s%s"</span><span>,</span> <span>line</span><span>,</span> <span>"\r\n"</span><span>));</span>
            <span>}</span>
            <span>return</span> <span>Mono</span><span>.</span><span>just</span><span>(</span><span>result</span><span>.</span><span>toString</span><span>());</span>
        <span>}</span><span>catch</span><span>(</span><span>IOException</span> <span>e</span><span>)</span> <span>{</span>
        <span>}</span>
        <span>return</span> <span>Mono</span><span>.</span><span>empty</span><span>();</span>
    <span>}</span>
<span>...</span>
...
    @Get(uri="/message", produces = "text/plain;charset=utf-8")
    public Mono<String> getShiftJisText() throws IOException {
        HttpRequest<?> req = HttpRequest.GET("http://localhost:8085/sample.txt")
            .contentType(MediaType.TEXT_JSON_TYPE);
        // receiving data as ByteBuffer
        HttpResponse<ByteBuffer> res = Mono.from(httpClient.exchange(req, ByteBuffer.class)).block();
        if(res.status() != HttpStatus.OK) {
            return Mono.empty();
        }
        // set encoding and read data
        try(ByteArrayInputStream input = new ByteArrayInputStream(res.body().toByteArray());
            BufferedReader br = new BufferedReader(new InputStreamReader(input, "SJIS"))) {            
            String line = "";
            StringBuilder result = new StringBuilder();
            while((line = br.readLine()) != null) {
                result.append(String.format("%s%s", line, "\r\n"));
            }
            return Mono.just(result.toString());
        }catch(IOException e) {
        }
        return Mono.empty();
    }
...

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Result

こんにちは
こんにちは
こんにちは

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• Micronaut HTTP Client
• InputStreamReader – Java Platform SE 8
• BufferedReader – Java Platform SE 8

原文链接：[Micronaut] Receiving Japanese(Shift-JIS) data as HTTPResponse