Android基础--XML序列化(XmlSerializer)

1.封装节点的JavaBean

public class City {
    private String name;
    private String temp;
    private String pm25;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getTemp() {
        return temp;
    }
    public void setTemp(String temp) {
        this.temp = temp;
    }
    public String getPm25() {
        return pm25;
    }
    public void setPm25(String pm25) {
        this.pm25 = pm25;
    }
    @Override
    public String toString() {
        return "City [name=" + name + ", temp=" + temp + ", pm25=" + pm25 + "]";
    }
    public City(String name, String temp, String pm25) {
        super();
        this.name = name;
        this.temp = temp;
        this.pm25 = pm25;
    }
    public City() {
        super();
    }
    
}

 

2.生成xml的MainActivity.java ,其中createXmlFile是绑定在一个Button控件上的点击事件

package com.itheima.xmlserializer;

import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import org.xmlpull.v1.XmlSerializer;

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.util.Xml;
import android.view.View;

import com.itheima.xmlserializer.domain.City;

public class MainActivity extends Activity {
    List<City> cityList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        cityList = new ArrayList<City>();
        City city = null;
        for (int i = 0; i < 5; i++) {
            city = new City("城市" + i, 20 + i + "", 100 + i + "");
            cityList.add(city);
        }
    }

    public void createXmlFile(View v) {
        // 判断当前SD卡是否可用
        if (Environment.getExternalStorageState().equals(
                Environment.MEDIA_MOUNTED)) {
            // 指定存放xml文件的位置
            File file = new File(Environment.getExternalStorageDirectory(),
                    "info.xml");
            // 获得XML序列化器
            XmlSerializer xs = Xml.newSerializer();
            OutputStream os = null;
            try {
                //OutputStream ：指定文件的保存路径
                //encoding：指定生成的xml文件的编码
                os = new FileOutputStream(file);
                xs.setOutput(os, "UTF-8");
                // 开始生成文件
                // 设置xml文件第一行<?xml encoding = ? standalone=?>
                xs.startDocument("UTF-8", true);
                //生成根节点开始标签
                xs.startTag(null, "weather");
                for (City city : cityList) {
                    xs.startTag(null, "city");
                    
                    xs.startTag(null, "name");
                    //生成文本节点
                    xs.text(city.getName());
                    xs.endTag(null, "name");
                    
                    xs.startTag(null, "temp");
                    //生成文本节点
                    xs.text(city.getTemp());
                    xs.endTag(null, "temp");
                    
                    xs.startTag(null, "pm25");
                    //生成文本节点
                    xs.text(city.getPm25());
                    xs.endTag(null, "pm25");
                    
                    xs.endTag(null, "city");
                }
                //生成根节点结束标签
                xs.endTag(null, "weather");
                xs.endDocument();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    }

}

 

3.生成的XML文件如下,因为没有换行,所有可读性差一些

<?xml version='1.0' encoding='UTF-8' standalone='yes' ?><weather><city><name>城市0</name><temp>20</temp><pm25>100</pm25></city><city><name>城市1</name><temp>21</temp><pm25>101</pm25></city><city><name>城市2</name><temp>22</temp><pm25>102</pm25></city><city><name>城市3</name><temp>23</temp><pm25>103</pm25></city><city><name>城市4</name><temp>24</temp><pm25>104</pm25></city></weather>