Android App中读取XML与JSON格式数据的基本方法示例

内容摘要
XML

假如有这样一个XML格式的数据:




<&#63;xml version="1.0" encoding="utf-8"&#63;>
<resources>
<customer name="luopeng" age="21" gender="1" emial="dylankee
文章正文

XML
假如有这样一个XML格式的数据:

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<?xml version="1.0" encoding="utf-8"?>
<resources>
<customer name="luopeng" age="21" gender="1"   emial="dylankeepmoving@163.com"/>
<customer name="dylan" age="22" gender="2" emial="710097663@qq.com"/>
<customer name="android" age="6" gender="2" emial="android@gmail.com"/>
</resources>

下面我们来编写一个类来读取,此类的作用是点击按钮后在EditView上显示资源文件(一个XML)中的内容,此例中会使用到XMLResourceParser

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public class TestXmlResourceParserActivity extends Activity {
private EditText et;
private Button myButton;
 
@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
 
  // 变量在内部类中使用的前提是此变量必须是final修饰的
  myButton = (Button) this.findViewById(R.id.btn01);
  et = (EditText) this.findViewById(R.id.edittext01);
  myButton.setOnClickListener(new OnClickListener() {
    StringBuilder sb = new StringBuilder("");
    Resources res = getResources();
    XmlResourceParser xrp = res.getXml(R.xml.test);
 
    @Override
    public void onClick(View v) {
      int counter = 0;
      try {
        // 判断是否到了文件的结尾
        while (xrp.getEventType() != XmlResourceParser.END_DOCUMENT) {
          //文件的内容的起始标签开始,注意这里的起始标签是test.xml文件里面<resources>标签下面的第一个标签
          if (xrp.getEventType() == XmlResourceParser.START_TAG) {
            String tagname = xrp.getName();
            if (tagname.endsWith("customer")) {
              counter++;
              sb.append("这是第" + counter + "客户"+"\n");
              sb.append("姓名:"+xrp.getAttributeValue(0)+"\n");
              sb.append("年龄:"+xrp.getAttributeValue(1)+"\n");
              sb.append("性别:"+xrp.getAttributeValue(2)+"\n");
              sb.append("邮箱:"+xrp.getAttributeValue(3)+"\n\n");
            }
          }
          xrp.next();
        }
        et.setText(sb.toString());
      } catch (XmlPullParserException e) {
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  });
}

JSON
创建JSON数据

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try {
    //首先创建对象中的一个单个键值对
    JSONObject root = new JSONObject();
    root.put("cat", "it");
    //另一个键值对的值是一个数组,数组里装了3个JSON对象,所以再分别搞3个JSONObject对象存放键值对
    JSONObject lan1 = new JSONObject();
    lan1.put("id", "1");
    lan1.put("ide", "Eclipse");
    lan1.put("name","Java");
    JSONObject lan2 = new JSONObject();
    lan2.put("id", "2");
    lan2.put("ide", "XCode");
    lan2.put("name","Swift");
    JSONObject lan3 = new JSONObject();
    lan3.put("id", "2");
    lan3.put("ide", "Visual Studio");
    lan3.put("name","C#");
    //在将这3个对象存入一个数组
    JSONArray array = new JSONArray();
    array.put(lan1);
    array.put(lan2);
    array.put(lan3);
    //再将数组作为键"languages"的值,构成一个对象
    root.put("languages", array);
    //本例中只将内容输出出来
    System.out.println(root.toString());
 
  } catch (JSONException e) {
    e.printStackTrace();
  }

读取JSON数据
assets/test.json

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{
  "languages":[
    {"id":1,"ide":"Eclipse","name":"Java"},
    {"id":2,"ide":"XCode","name":"Swift"},
    {"id":3,"ide":"Visual Studio","name":"C#"},
  ],
  "cat","it"
}
try {
    InputStream is = getResources().getAssets().open("test.json");
    InputStreamReader isr = new InputStreamReader(is, "UTF-8");
    BufferedReader br = new BufferedReader(isr);
    //将文本中的数据,都读取到一个StringBuilder当中
    String line;
    StringBuilder builder = new StringBuilder();
    while((line=br.readLine()) != null ){
      builder.append(line);
    }
    br.close();
    isr.close();
 
    JSONObject root = new JSONObject(builder.toString());
    //根据键,获得键对应的值,由于值是String类型,所以用getString
    System.out.println("cat="+root.getString("cat"));
    //根据键,获得键对应的数组,由于值是一个数组,所以用getJSONArray
    JSONArray array = root.getJSONArray("languages");
    //由于要遍历数组,所以创建一个for循环
    for(int i=0; i < array. length(); i++){
      //由于每一个数组当中的元素,也是一个新的JSON对象
      JSONObject lan = array.getJSONObject(i);
      System.out.println("-------------------");
      System.out.println("id="+lan.getInt("id"));
      System.out.println("ide="+lan.getString("name"));
      System.out.println("name="+lan.getString("name"));
      Log.i("tag","-------");
    }
 
  } catch (IOException e) {
    e.printStackTrace();
  } catch (JSONException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
  }

   


代码注释

作者:喵哥笔记

IDC笔记

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