【JSON】数据解析

1、保存数组

public class MyJSONDemo extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.main);
        String data[] = new String[] { "www.mldnjava.cn", "lixinghua",
                "bbs.mldn.cn" }; // 要输出的数据
        // 建立最外面的节点对象
        JSONObject allData = new JSONObject(); 
        JSONArray sing = new JSONArray(); // 定义数组
        // 将数组内容配置到相应的节点
        for (int x = 0; x < data.length; x++) { 
            // 每一个包装的数据都是JSONObject
            JSONObject temp = new JSONObject(); 
            try {
                temp.put("myurl", data[x]);
            } catch (JSONException e) {
                e.printStackTrace();
            }
            sing.put(temp); // 保存多个JSONObject
        }
        try {
            allData.put("urldata", sing);
        } catch (JSONException e) {
            e.printStackTrace();
        }
        if (!Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED)) { // 不存在不操作
            return; // 返回到程序的被调用处
        }
        // 要输出文件的路径
        File file = new File(Environment.getExternalStorageDirectory()
                + File.separator + "mldndata" + File.separator + "json.txt"); 
        if (!file.getParentFile().exists()) { // 文件不存在
            file.getParentFile().mkdirs(); // 创建文件夹
        }
        PrintStream out = null;
        try {
            out = new PrintStream(new FileOutputStream(file));
            // 将数据变为字符串后保存
            out.print(allData.toString()); 
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                out.close(); // 关闭输出
            }
        }
    }
}

2、复杂数据

public class MyJSONDemo extends Activity {
    private String nameData[] = new String[] { "李兴华", "魔乐科技", "MLDN" };
    private int ageData[] = new int[] { 30, 5, 7 };
    private boolean isMarraiedData[] = new boolean[] { false, true, false };
    private double salaryData[] = new double[] { 3000.0, 5000.0, 9000.0 };
    private Date birthdayData[] = new Date[] { new Date(), new Date(),
            new Date() };
    private String companyName = "北京魔乐科技软件学院（MLDN软件实训中心）" ;
    private String companyAddr = "北京市西城区美江大厦6层" ;
    private String companyTel = "010-51283346" ;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.main);
        JSONObject allData = new JSONObject(); // 建立最外面的节点对象
        JSONArray sing = new JSONArray(); // 定义数组
        for (int x = 0; x < this.nameData.length; x++) { // 将数组内容配置到相应的节点
            JSONObject temp = new JSONObject(); // 每一个包装的数据都是JSONObject
            try {
                temp.put("name", this.nameData[x]);
                temp.put("age", this.ageData[x]);
                temp.put("married", this.isMarraiedData[x]);
                temp.put("salary", this.salaryData[x]);
                temp.put("birthday", this.birthdayData[x]);
            } catch (JSONException e) {
                e.printStackTrace();
            }
            sing.put(temp); // 保存多个JSONObject
        }
        try {
            allData.put("persondata", sing);
            allData.put("company", this.companyName) ; 
            allData.put("address", this.companyAddr) ;
            allData.put("telephone", this.companyTel) ;
        } catch (JSONException e) {
            e.printStackTrace();
        }
        if (!Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED)) { // 不存在不操作
            return; // 返回到程序的被调用处
        }
        File file = new File(Environment.getExternalStorageDirectory()
                + File.separator + "mldndata" + File.separator + "json.txt"); // 要输出文件的路径
        if (!file.getParentFile().exists()) { // 文件不存在
            file.getParentFile().mkdirs(); // 创建文件夹
        }
        PrintStream out = null;
        try {
            out = new PrintStream(new FileOutputStream(file));
            out.print(allData.toString()); // 将数据变为字符串后保存
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                out.close(); // 关闭输出
            }
        }
    }
}

3、解析数组

public class MyJSONDemo extends Activity {
    private TextView msg = null ;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.main);
        this.msg = (TextView) super.findViewById(R.id.msg) ;
        String str = "[{\"id\":1,\"name\":\"李兴华\",\"age\":30},"
                + "{\"id\":2,\"name\":\"MLDN\",\"age\":10}]";
        StringBuffer buf = new StringBuffer() ;
        try {
            List<Map<String,Object>> all = this.parseJson(str) ;
            Iterator<Map<String,Object>> iter = all.iterator() ;
            while(iter.hasNext()){
                Map<String,Object> map = iter.next() ;
                buf.append("ID：" + map.get("id") + "，姓名：" + map.get("name")
                        + "，年龄：" + map.get("age") + "\n");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        this.msg.setText(buf) ;
    }

    private List<Map<String, Object>> parseJson(String data) throws Exception {
        List<Map<String, Object>> all = new ArrayList<Map<String, Object>>();
        JSONArray jsonArr = new JSONArray(data); // 是数组
        for (int x = 0; x < jsonArr.length(); x++) {
            Map<String, Object> map = new HashMap<String, Object>();
            JSONObject jsonObj = jsonArr.getJSONObject(x);
            map.put("id", jsonObj.getInt("id"));
            map.put("name", jsonObj.getString("name"));
            map.put("age", jsonObj.getInt("age"));
            all.add(map);
        }
        return all;
    }
}

4、复杂解析

public class MyJSONDemo extends Activity {
    private TextView msg = null ;

    @SuppressWarnings("unchecked")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.main);
        this.msg = (TextView) super.findViewById(R.id.msg) ;
        String str = "{\"memberdata\":[{\"id\":1,\"name\":\"李兴华\",\"age\":30},"
                + "{\"id\":2,\"name\":\"MLDN\",\"age\":10}],\"company\":\"北京魔乐科技软件学院\"}";
        StringBuffer buf = new StringBuffer() ;
        try {
            Map<String, Object> result = this.parseJson(str) ;    // 解析文本
            buf.append("公司名称：" + result.get("company") + "\n");
            List<Map<String,Object>> all = (List<Map<String,Object>>) result.get("memberdata") ; 
            Iterator<Map<String,Object>> iter = all.iterator() ;
            while(iter.hasNext()){
                Map<String,Object> map = iter.next() ;
                buf.append("ID：" + map.get("id") + "，姓名：" + map.get("name")
                        + "，年龄：" + map.get("age") + "\n");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        this.msg.setText(buf) ;
    }

    private Map<String, Object> parseJson(String data) throws Exception {
        Map<String, Object> allMap = new HashMap<String, Object>();
        JSONObject allData = new JSONObject(data) ;    // 全部的内容变为一个项
        allMap.put("company", allData.getString("company")); // 取出项
        JSONArray jsonArr = allData.getJSONArray("memberdata"); // 取出数组
        List<Map<String,Object>> all = new ArrayList<Map<String,Object>>() ;
        for (int x = 0; x < jsonArr.length(); x++) {
            Map<String, Object> map = new HashMap<String, Object>();
            JSONObject jsonObj = jsonArr.getJSONObject(x);
            map.put("id", jsonObj.getInt("id"));
            map.put("name", jsonObj.getString("name"));
            map.put("age", jsonObj.getInt("age"));
            all.add(map);
        }
        allMap.put("memberdata", all) ;
        return allMap;
    }
}