Question

平台：Android Studio 2.3.3
操作系统：Windows 10

我已将所有httpcomponents-client-4.5.3 lib添加到我的项目库中，并创建新类HttpUtil：

package com.zsh.ricky.zsh.util;

import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;

/**
 * Created by Ricky on 2017/9/29.
 */

public class HttpUtil {
    //创建HttpClient对象
    private static CloseableHttpClient httpClient = HttpClients.createDefault();
    private static final String BASE_URL = "http://10.0.2.2:8080/CGService/";

    /**
     * 向服务器发送get请求
     * @param url 发送请求的url
     * @return 服务器响应字段
     * @throws ExecutionException
     * @throws InterruptedException
     */
    public static String getRequest(final String url)
            throws ExecutionException, InterruptedException
    {
        FutureTask<String> task = new FutureTask<String>(
                new Callable<String>() {
                    @Override
                    public String call() throws Exception {
                        //创建 HttpGet对象
                        HttpGet get = new HttpGet(BASE_URL + url);
                        //发送get请求
                        CloseableHttpResponse response = httpClient.execute(get);
                        String result = null;

                        try {
                            HttpEntity entity = response.getEntity();
                            if (entity != null)
                            {
                                //获取服务器响应字符串
                                result = EntityUtils.toString(entity);
                            }
                        } finally {
                            response.close();
                        }

                        return result;
                    }
                }
        );
        new Thread(task).start();
        return task.get();
    }

    /**
     * 处理POST请求
     * @param url 发送请求的url
     * @param rawParams 请求参数
     * @return 服务器响应字符串
     * @throws ExecutionException
     * @throws InterruptedException
     */
    public static String postRequest(final String url,
                                     final Map<String, String> rawParams)
            throws ExecutionException, InterruptedException
    {
        FutureTask<String> task = new FutureTask<String>(
                new Callable<String>() {
                    @Override
                    public String call() throws Exception {
                        //创建httpPost对象
                        HttpPost post = new HttpPost(BASE_URL + url);
                        //如果传递的参数比较多，对参数进行封装
                        List<NameValuePair> params = new ArrayList<>();
                        for (String key : rawParams.keySet())
                        {
                            //封装请求参数
                            params.add(new BasicNameValuePair(key, rawParams.get(key)));
                        }
                        //设置请求参数
                        post.setEntity(new UrlEncodedFormEntity(params, "utf-8"));
                        //发送post请求
                        CloseableHttpResponse response = httpClient.execute(post);
                        String result = null;

                        try {
                            HttpEntity entity = response.getEntity();
                            if (entity != null)
                            {
                                //获取响应字符串
                                result = EntityUtils.toString(entity);
                            }
                        } finally {
                            response.close();
                        }

                        return result;
                    }
                }
        );
        new Thread(task).start();
        return task.get();
    }

    public static String get(final String url)
            throws IOException
    {
        //创建 HttpGet对象
        HttpGet get = new HttpGet(BASE_URL + url);
        //发送get请求

        CloseableHttpResponse response = httpClient.execute(get);
        String result = null;

        try {
            HttpEntity entity = response.getEntity();
            if (entity != null)
            {
                //获取服务器响应字符串
                result = EntityUtils.toString(entity);
            }
        } finally {
            response.close();
        }

        return result;
    }
}

当我想在MainActivity中初始化类时：

package com.zsh.ricky.zsh;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import com.zsh.ricky.zsh.util.DialogUtil;
import com.zsh.ricky.zsh.util.HttpUtil;
public class MainActivity extends AppCompatActivity {

    private TextView mainText;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String url = "login";
        String result = "";

        try {
            result = HttpUtil.getRequest(url);
        } catch (Exception e) {
            DialogUtil.showDialog(this, "服务器响应出错！", false);
            e.printStackTrace();
        }

        mainText = (TextView) this.findViewById(R.id.main_text);
        mainText.setText(result);
    }
}

应用程序将停止，当我调试此代码时，IDE总是跳转到Looper.java。转移，IDE无法解析Looper中的某些导入类。

我完全不知道这个问题，也许sdk平台不对。

Answer 1

将此dependency添加到 build.gradle

dependencies {
    compile 'com.intellij:annotations:+@jar'
    ...
}

或者

dependencies {
    compile 'com.android.support:support-annotations:+'
}

Answer 2

您应该清理项目，然后同步项目并重建项目。它工作正常。但如果没有，你应该关闭android工作室并重新打开它。

无法初始化类

2 个答案: