JAVA_Gson_example

package cn.kjxy.GSON;

import java.util.List;

import cn.kjxy.JSON.HttpHelpers;

import com.google.gson.Gson;

/**
 * gson解析json对象 ：
 * 注意：1.建立的属性或者对象名必须与json数据中的一致才能解析出来
 *         2。需导入gson-2.2.1.jar包
 *         工具类需导入：commons-logging-1.1.1.jar
 *                 httpclient-4.1.2.jar
 *                 httpcore-4.1.2.jar
 * 
 * @author Administrator
 *
 */
class Food {
    private int ret;
    private List<Data> data;

    @Override
    public String toString() {
        return "Food [ret=" + ret + ", data=" + data + "]";
    }

}

class Data {

    private int id;// ": "8289",
    private String title;// ": "油焖大虾",
    private String pic;// ": "http://www.qubaobei.com/ios/cf/uploadfile/132/9/8289.jpg",
    private int collect_num;// ": "1544",
    private String food_str;// ": "大虾 葱 生姜 植物油 料酒",
    private int num;// ": 1544

    @Override
    public String toString() {
        return "Data [id=" + id + ", title=" + title + ", pic=" + pic
                + ", collect_num=" + collect_num + ", food_str=" + food_str
                + ", num=" + num + "]";
    }

}

public class Demo2 {
    public static void main(String[] args) {
        // gson解析json对象
        String json1 = HttpHelpers
                .getResourceByInternet("http://www.qubaobei.com/ios/cf/dish_list.php?stage_id=1&page=1&limit=20");
        parserJsonByGson(json1);
    }

    private static void parserJsonByGson(String json1) {
        // TODO Auto-generated method stub
        Gson gson = new Gson();
        Food food = gson.fromJson(json1, Food.class);
        System.out.println(food);
    }

}

工具类：

package cn.kjxy.JSON;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

/**
 * 请求网络的工具类
 * 
 * @author Administrator
 *
 */
public class HttpHelpers {

    /**
     * 下载图片 保存到byte类型的数组中
     * 
     * @param path
     *            地址
     * @return byte[]
     */
    public static byte[] downLoadImg(String path) {
        BufferedInputStream bis = null;
        try {
            // 1,创建HttpClient对象 Android6.0之前可以使用
            HttpClient httpClient = new DefaultHttpClient();
            // 2,创建请求对象+指定地址
            HttpGet httpGet = new HttpGet(path);
            // 3,执行请求 获得HttpResponse对象
            HttpResponse response = httpClient.execute(httpGet);
            // 4,获得响应码
            int code = response.getStatusLine().getStatusCode();
            if (code == 200) {
                // 5,得到响应的HttpEntity对象
                HttpEntity responseEntity = response.getEntity();
                // 方法一
                // bis = new BufferedInputStream(responseEntity.getContent());
                // byte b[] = toByteArray(bis);
                // return b;

                // 方法二
                return EntityUtils.toByteArray(responseEntity);

            }

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (bis != null) {
                try {
                    bis.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }

        return null;

    }

    /**
     * 把图片下载到本地磁盘
     * 
     * @param path
     */
    public static void downLoadImgToLocal(String path) {
        BufferedInputStream bis = null;
        BufferedOutputStream boStream = null;
        try {
            // 1,创建HttpClient对象 Android6.0之前可以使用
            HttpClient httpClient = new DefaultHttpClient();
            // 2,创建请求对象+指定地址
            HttpGet httpGet = new HttpGet(path);
            // 3,执行请求 获得HttpResponse对象
            HttpResponse response = httpClient.execute(httpGet);
            // 4,获得响应码
            int code = response.getStatusLine().getStatusCode();
            if (code == 200) {
                // 5,得到响应的HttpEntity对象
                HttpEntity responseEntity = response.getEntity();
                // 方法一
                // bis = new BufferedInputStream(responseEntity.getContent());
                // byte b[] = toByteArray(bis);

                // 方法二
                byte b[] = EntityUtils.toByteArray(responseEntity);
                String endsWith = path.substring(path.lastIndexOf("."));
                boStream = new BufferedOutputStream(new FileOutputStream(
                        (int) (Math.random() * 100) + endsWith));
                boStream.write(b);

            }

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (bis != null) {
                try {
                    bis.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (boStream != null) {
                try {
                    boStream.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }

    }

    /**
     * 从互联网获取文本 json xml
     * 
     * @param path
     *            地址
     * @return 获取到的文本数据
     */

    public static String getResourceByInternet(String path) {
        BufferedReader bReader = null;
        try {
            // 1,创建HttpClient对象 Android6.0之前可以使用
            HttpClient httpClient = new DefaultHttpClient();
            // 2,创建请求对象+指定地址
            HttpGet httpGet = new HttpGet(path);
            // 3,执行请求 获得HttpResponse对象
            HttpResponse response = httpClient.execute(httpGet);
            // 4,获得响应码
            int code = response.getStatusLine().getStatusCode();
            if (code == 200) {
                // 得到HttpEntity对象
                HttpEntity responseEntity = response.getEntity();
                // 方法一
                // bReader = new BufferedReader(new
                // InputStreamReader(responseEntity.getContent()));
                // StringBuilder sbBuilder = new StringBuilder();
                // String line = null;
                // while ((line = bReader.readLine()) != null) {
                // sbBuilder.append(line);
                // }
                //
                // return sbBuilder.toString();

                // 方法二
                return EntityUtils.toString(responseEntity);

            }

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (bReader != null) {
                try {
                    bReader.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }

        return null;

    }

    public static byte[] toByteArray(BufferedInputStream bufferedInputStream) {
        byte b[] = new byte[1024 * 1024];
        int len = 0;
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            while ((len = bufferedInputStream.read(b)) != -1) {
                baos.write(b, 0, len);
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return baos.toByteArray();

    }

    public static String upLoadData(String path, Map<String, String> map) {
        BufferedReader bReader = null;
        try {
            // 1,创建HttpClient对象 Android6.0之前可以使用
            HttpClient httpClient = new DefaultHttpClient();
            // 2,创建请求对象+指定地址
            HttpPost httpPost = new HttpPost(path);
            // 设置用于发送到服务端的参数
            List<NameValuePair> list = new ArrayList<NameValuePair>();

            for (String string : map.keySet()) {
                list.add(new BasicNameValuePair(string, map.get(string)));
            }
            HttpEntity requestEntity = new UrlEncodedFormEntity(list, "gbk");
            httpPost.setEntity(requestEntity);

            // 3,执行请求 获得HttpResponse对象
            HttpResponse response = httpClient.execute(httpPost);
            // 4,获得响应码
            int code = response.getStatusLine().getStatusCode();
            if (code == 200) {
                // 得到HttpEntity对象
                HttpEntity responseEntity = response.getEntity();
                // 方法一
                // bReader = new BufferedReader(new
                // InputStreamReader(responseEntity.getContent()));
                // StringBuilder sbBuilder = new StringBuilder();
                // String line = null;
                // while ((line = bReader.readLine()) != null) {
                // sbBuilder.append(line);
                // }
                //
                // return sbBuilder.toString();

                // 方法二
                return EntityUtils.toString(responseEntity, "gbk");

            }

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if (bReader != null) {
                try {
                    bReader.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }

        return null;

    }

    public static void main(String[] args) {
        byte b[] = downLoadImg("http://images.china.cn/attachement/jpg/site1000/20140313/844bf52c7d7c148b8abc05.jpg");
        BufferedOutputStream bufferedOutputStream;
        try {
            bufferedOutputStream = new BufferedOutputStream(
                    new FileOutputStream("ceo.jpg"));
            // bufferedOutputStream.write(b);

        } catch (FileNotFoundException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        // downLoadImgToLocal("http://images.china.cn/attachement/jpg/site1000/20140313/844bf52c7d7c148b8abc05.jpg");

        // System.out.println(getResourceByInternet("http://www.doukantv.com/api/hot/?type=movie&cli=ipad&sys_ver=7.1.1&ver=2.1"));
        Map<String, String> map = new HashMap<String, String>();
        map.put("uname", "张三");
        map.put("pwd", "admin");
        System.out.println(upLoadData(
                "http://172.20.136.5:8080/2016_05_27_server/login", map));

    }

}