分享程序员开发的那些事...
更新时间：2022-08-16 08:42:12
新建Android项目
编写AndroidManifest.xml,使本Android项目具有单元测试功能和写外设的权限。
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.itheima28.xmldemo"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<!—用于单元测试—>
<instrumentation
android:name="android.test.InstrumentationTestRunner"
android:targetPackage="com.itheima28.xmldemo">
</instrumentation>
<!—写外设的权限à
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<!—单元测试所需à
<uses-library android:name="android.test.runner"/>
<activity
android:name="com.itheima28.xmldemo.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
3 Person对象
package com.itheima28.xmldemo;
public class Person {
private int id;
private String name;
private int age;
@Override
public String toString() {
return "Person [id=" + id + ", name=" + name + ", age=" + age + "]";
}
public Person() {
super();
}
public Person(int id, String name, int age) {
super();
this.id = id;
this.name = name;
this.age = age;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
4 写xml文件和读xml文件的代码
package com.itheima28.xmldemo.test;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.List;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlSerializer;
import android.os.Environment;
import android.test.AndroidTestCase;
import android.util.Log;
import android.util.Xml;
import com.itheima28.xmldemo.Person;
public class TestCase extends AndroidTestCase {
/**
* 测试写xml文件
*/
public void testWriteXml() {
writeXmlToLocal();
}
/**
* 测试读xml文件
*/
public void testReadXml() {
List<Person> personList = parseXmlFromLocal();
for (Person person : personList) {
Log.i("TestCase",person.toString());
}
}
/**
* 写xml文件到本地
*/
private void writeXmlToLocal() {
List<Person> personList = getPersonList();
//获得序列化对象
XmlSerializer serializer = Xml.newSerializer();
try {
//测试获得到的位置是：/storage/emulated/0
File path = new File(Environment.getExternalStorageDirectory(),"persons.xml");
FileOutputStream fos = new FileOutputStream(path);
//指定序列化对象输出的位置和编码
serializer.setOutput(fos,"utf-8");
//写开始<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
serializer.startDocument("utf-8", true);
//<persons>
serializer.startTag(null, "persons");
for (Person person : personList) {
//开始写入
serializer.startTag(null, "person");
serializer.attribute(null, "id", String.valueOf(person.getId()));
//写名字<name>
serializer.startTag(null, "name");
serializer.text(person.getName());
//</name>
serializer.endTag(null, "name");
//写年龄
//<age>
serializer.startTag(null, "age");
serializer.text(String.valueOf(person.getAge()));
//</age>
serializer.endTag(null, "age");
//</persons>
serializer.endTag(null, "person");
}
//</persons>
serializer.endTag(null, "persons");
//结束
serializer.endDocument();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 用于生成一个List的Person集合
* @return
*/
private List<Person> getPersonList() {
List<Person> personList = new ArrayList<Person>();
for (int i = 0; i < 30; i++) {
personList.add(new Person(i,"wang" + i, 18 + i));
}
return personList;
}
/**
* 解析xml文件并将xml文件中内容写List集合中
* @return
*/
private List<Person> parseXmlFromLocal() {
try {
File path = new File(Environment.getExternalStorageDirectory(),"persons.xml");
FileInputStream fis = new FileInputStream(path);
//获得pull解析器对象
XmlPullParser parser = Xml.newPullParser();
//指定解析的文件的编码格式
parser.setInput(fis,"utf-8");
//获得时间类型
int eventType = parser.getEventType();
List<Person> personList = null;
Person person = null;
String id;
while (eventType != XmlPullParser.END_DOCUMENT) {
//获取当前节点的名称
String tagName = parser.getName();
switch (eventType) {
//获得当前节点的名称 <person>
case XmlPullParser.START_TAG:
//<persons>
if("persons".equals(tagName)) {
personList = new ArrayList<Person>();
} else if ("person".equals(tagName)) { //<person id="1">
person = new Person();
id = parser.getAttributeValue(null,"id");
person.setId(Integer.valueOf(id));
} else if("name".equals(tagName)) {
person.setName(parser.nextText());
} else if("age".equals(tagName)) { //<age>
person.setAge(Integer.parseInt(parser.nextText()));
}
break;
//</persons>
case XmlPullParser.END_TAG:
if ("person".equals(tagName)) {
//需要把上面设置好的person对象添加到集合中
personList.add(person);
}
break;
default:
break;
}
//获得下一个事件类型
eventType = parser.next();
}
return personList;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
5 设置Log过滤器
6、控制台输出结果