XmlSerializer

一、如何使用XmlSerializer创建xml文件

XmlSerializer serializer = Xml.newSerializer();
serializer.setOutput(fos,"utf-8"); 
//开始文档(字符集，文档是否独立) 
serializer.startDocument("utf-8",true); 
//开始一个标签(参数:命名空间，标签名) 
serializer.startTag(null,"book");
//结束一个标签 
serializer.endTag(null, "book");
//结束文档 
serializer.endDocument();

 

二、xml序列化和反序列化案例

1.UI搭建（代码如下）

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="44dp"
        android:layout_marginLeft="44dp"
        android:layout_marginTop="36dp"
        android:text="保存Xml"
        android:onClick="xmlSave"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="32dp"
        android:layout_marginLeft="32dp"
        android:text="读取Xml"
        app:layout_constraintBottom_toBottomOf="@+id/button"
        app:layout_constraintStart_toEndOf="@+id/button"
        app:layout_constraintTop_toTopOf="@+id/button"
        app:layout_constraintVertical_bias="0.0" />

</androidx.constraintlayout.widget.ConstraintLayout>

2.数据实体类（代码如下）

package com.hiscene.testxml;

public class Book {

    String name;
    String author;
    double price;
}

3.具体逻辑

package com.hiscene.testxml;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Xml;
import android.view.View;

import org.xmlpull.v1.XmlSerializer;

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

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    //保存xml
    public void xmlSave(View view)
    {
        List<Book> list =new ArrayList<>();
        for (int i=1;i<=10;i++)
        {
            Book book =new Book();
            book.name="西游记"+i;
            book.author="吴承恩"+i;
            book.price=i;
            list.add(book);
        }

        XmlSerializer serializer= Xml.newSerializer();
        File file =new File(this.getFilesDir(),"books.xml");
        try {
            OutputStream out =new FileOutputStream(file);
            serializer.setOutput(out,"utf-8");
            serializer.startDocument("utf-8",true);

            serializer.startTag(null,"books");

            for (Book book:list)
            {
                serializer.startTag(null,"book");

                serializer.startTag(null,"name");
                serializer.text(book.name);
                serializer.endTag(null,"name");

                serializer.startTag(null,"author");
                serializer.text(book.author);
                serializer.endTag(null,"author");

                serializer.endTag(null,"book");
            }

            serializer.endTag(null,"books");

            serializer.endDocument();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

    }

}