向webview注入网络上的js，就需要请求js的url。但不允许在主线程直接发http请求，需要开子线程，开了子线程后，子线程就自己运行，主线程也自己运行，但是我的主线程需要子线程的结果才能继续往下操作，不然没有意义。我这个不适合网络请求回调，如下是一种简单的解决方式。
就是把请求结果绑定到成员变量。然后检查成员变量。这样就不会造成子线程还没运行完，就迅速获取js的内容，导致是空的，向注入webview注入js失败，。
package com.xx.view; import java.util.concurrent.TimeUnit; import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response; /**
* Created by wj49476 on 2018/3/23.
*/ public class ScriptDownloader { private static final String urlPrefix = "http://10.0.4.147:8301/jss/crawl/";
private String scriptName;
private byte[] jsScriptContent;
private int times = 0; public ScriptDownloader(String scriptNmae){
this.scriptName = scriptNmae;
} private void get() {
final String url = urlPrefix + scriptName;
new Thread(new Runnable() {
@Override
public void run() {
final Request.Builder builder = new Request.Builder();
final OkHttpClient client = new OkHttpClient.Builder()
.readTimeout(30, TimeUnit.SECONDS)
.connectTimeout(30, TimeUnit.SECONDS)
.writeTimeout(30, TimeUnit.SECONDS)
.build(); //设置各种超时时间
builder.url(url);
System.out.println("请求的js脚本url是：" + url);
final Request request = builder.build();
try (Response response = client.newCall(request).execute()) {
jsScriptContent = (response.body().bytes());
System.out.println(new String(jsScriptContent));
}catch (Exception e){
System.out.println("请求脚本出错");
e.printStackTrace();
}
}
}).start();
} public byte[] getJsScriptContent(){ if (times % 5 == 0){
get();
}
times += 1;
try{
Thread.sleep(1000);
}catch (Exception e){
e.printStackTrace();
} if (jsScriptContent != null){
return jsScriptContent;
}else{
if (times < 20){
return getJsScriptContent();
}
else{
return null;
}
}
}
public static void main(String[] args) {
byte[] jsConet = new ScriptDownloader("credit/crccReport.js").getJsScriptContent();
System.out.println("注入的脚本内容是： " + new String(jsConet));
}
}
安卓不让做阻塞的io网络请求，但没说不让sleep。