这几天对接了一个WebSocket，一开始使用的Java_webSocket这个库，

    // https://mvnrepository.com/artifact/org.java-websocket/Java-WebSocket
    implementation 'org.java-websocket:Java-WebSocket:1.5.2'
    // https://mvnrepository.com/artifact/org.slf4j/slf4j-log4j12
    testImplementation 'org.slf4j:slf4j-log4j12:1.7.30'

使用着觉得不好封装，网上搜索了一番，看到这个
https://www.jianshu.com/p/57a91bd2b68f
觉得还可以，只是我只是对接一个接口而已，没必要这么复杂。
引用的库是

    // https://mvnrepository.com/artifact/com.google.code.gson/gson
    implementation 'com.google.code.gson:gson:2.8.8'

    // https://mvnrepository.com/artifact/com.squareup.okhttp3/okhttp
    implementation 'com.squareup.okhttp3:okhttp:4.9.1'

整了个java测试类，如下

package com.your.pkgname;

import android.support.annotation.NonNull;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.util.concurrent.TimeUnit;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.WebSocket;
import okhttp3.WebSocketListener;
import okio.ByteString;

/**
 * 使用okhttp来实现WebSocket
 * https://www.jianshu.com/p/57a91bd2b68f
 */
public class OkHttpWebSocket {
    private WebSocket mWebSocket;

    @Before
    public void setUp() throws Exception {
        final OkHttpClient client = new OkHttpClient.Builder()
                .readTimeout(3, TimeUnit.SECONDS)//设置读取超时时间
                .writeTimeout(3, TimeUnit.SECONDS)//设置写的超时时间
                .connectTimeout(3, TimeUnit.SECONDS)//设置连接超时时间
                .build();
        //连接地址
        final String url = "ws://your.url";
        //构建一个连接请求对象
        final Request request = new Request.Builder()
                .get()
                .url(url)
                .build();
        mWebSocket = client.newWebSocket(request, new WebSocketListener() {
            @Override
            public void onOpen(@NonNull WebSocket webSocket, @NonNull Response response) {
                super.onOpen(webSocket, response);
                System.out.println("onOpen");
            }

            @Override
            public void onMessage(@NonNull WebSocket webSocket, @NonNull String text) {
                super.onMessage(webSocket, text);
                System.out.println("onMessage,text = " + text);
            }

            @Override
            public void onMessage(@NonNull WebSocket webSocket, @NonNull ByteString bytes) {
                super.onMessage(webSocket, bytes);
                System.out.println("onMessage,bytes = " + bytes);
            }

            @Override
            public void onClosing(@NonNull WebSocket webSocket, @NonNull int code, String reason) {
                super.onClosing(webSocket, code, reason);
                System.out.println("onClosing");
            }

            @Override
            public void onClosed(@NonNull WebSocket webSocket, @NonNull int code, String reason) {
                super.onClosed(webSocket, code, reason);
                System.out.println("onClosed");
            }

            @Override
            public void onFailure(@NonNull WebSocket webSocket, @NonNull Throwable t, Response response) {
                super.onFailure(webSocket, t, response);
                System.out.println("onFailure reason = " + t.getLocalizedMessage());
            }
        });
    }

    @After
    public void tearDown() throws Exception {
        mWebSocket.close(0, "123");
    }

    @Test
    public void start() throws Exception {
        Thread.sleep(TimeUnit.SECONDS.toMillis(30));
    }
}

当运行结束时，回收资源时，出现了错误

    @After
    public void tearDown() throws Exception {
        mWebSocket.close(0, "123");
    }

提示错误如下：

ava.lang.IllegalArgumentException: Code must be in range [1000,5000): 0

    at okhttp3.internal.ws.WebSocketProtocol.validateCloseCode(WebSocketProtocol.kt:134)
    at okhttp3.internal.ws.RealWebSocket.close(RealWebSocket.kt:435)
    at okhttp3.internal.ws.RealWebSocket.close(RealWebSocket.kt:427)
    at com.your.pkgname.OkHttpWebSocket.tearDown(OkHttpWebSocket.java:80)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
    at org.junit.internal.runners.statements.RunAfters.invokeMethod(RunAfters.java:46)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:33)
    at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
    at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
    at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
    at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
    at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)

说是这个结束状态码只能是1000(包含)-5000(不含)；
然而这些值到底是什么意思呢？
而原接口只是如下：

/**
   * Attempts to initiate a graceful shutdown of this web socket. Any already-enqueued messages will
   * be transmitted before the close message is sent but subsequent calls to [send] will return
   * false and their messages will not be enqueued.
   *
   * This returns true if a graceful shutdown was initiated by this call. It returns false if
   * a graceful shutdown was already underway or if the web socket is already closed or canceled.
   *
   * @param code Status code as defined by
   *     [Section 7.4 of RFC 6455](http://tools.ietf.org/html/rfc6455#section-7.4).
   * @param reason Reason for shutting down, no longer than 123 bytes of UTF-8 encoded data (**not** characters) or null.
   * @throws IllegalArgumentException if [code] is invalid or [reason] is too long.
   */
  fun close(code: Int, reason: String?): Boolean

也没有相关的信息，打不开。
于是搜到了这个：
链接
https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent#Status_codes
于是用Chrome翻译了一下，截图如下：

图片1

图片2

初步算是解决了，tearDown代码改成如下：

    @After
    public void tearDown() throws Exception {
        mWebSocket.close(1000, "123");
    }

ok.不做深究了，暂时解决了就好。