Xstream-object-streams

XStream-オブジェクトストリーム

XStreamは、java.io.ObjectInputStreamおよびjava.io.ObjectOutputStreamの代替実装を提供するため、オブジェクトのストリームをXMLからシリアル化または非シリアル化できます。 これは、一度に1つのオブジェクトをメモリに保持し、オブジェクトの大きなセットを処理する場合に特に役立ちます。

構文：createObjectOutputStream（）

ObjectOutputStream objectOutputStream = xstream.createObjectOutputStream(
   new FileOutputStream("test.txt"));

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構文：createObjectInputStream（）

ObjectInputStream objectInputStream = xstream.createObjectInputStream(
   new FileInputStream("test.txt"));

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XStreamでオブジェクトストリームを使用してコードをテストしましょう。

C：\> XStream_WORKSPACE \ com \ finddevguides \ xstreamにXStreamTesterという名前のJavaクラスファイルを作成します。

ファイル：XStreamTester.java

package com.finddevguides.xstream;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.annotations.XStreamAlias;
import com.thoughtworks.xstream.io.xml.StaxDriver;

public class XStreamTester {
   public static void main(String args[]) {

      XStreamTester tester = new XStreamTester();
      XStream xstream = new XStream(new StaxDriver());

      xstream.autodetectAnnotations(true);

      Student student1 = new Student("Mahesh","Parashar");
      Student student2 = new Student("Suresh","Kalra");
      Student student3 = new Student("Ramesh","Kumar");
      Student student4 = new Student("Naresh","Sharma");

      try {

         ObjectOutputStream objectOutputStream = xstream.createObjectOutputStream(
            new FileOutputStream("test.txt"));

         objectOutputStream.writeObject(student1);
         objectOutputStream.writeObject(student2);
         objectOutputStream.writeObject(student3);
         objectOutputStream.writeObject(student4);
         objectOutputStream.writeObject("Hello World");

         objectOutputStream.close();

         ObjectInputStream objectInputStream = xstream.createObjectInputStream(
            new FileInputStream("test.txt"));

         Student student5 = (Student)objectInputStream.readObject();
         Student student6 = (Student)objectInputStream.readObject();
         Student student7 = (Student)objectInputStream.readObject();
         Student student8 = (Student)objectInputStream.readObject();

         String text = (String)objectInputStream.readObject();

         System.out.println(student5);
         System.out.println(student6);
         System.out.println(student7);
         System.out.println(student8);
         System.out.println(text);

      } catch (IOException e) {
         e.printStackTrace();

      } catch (ClassNotFoundException e) {
         e.printStackTrace();
      }
   }
}

@XStreamAlias("student")
class Student {

   private String firstName;
   private String lastName;

   public Student(String firstName, String lastName) {
      this.firstName = firstName;
      this.lastName = lastName;
   }

   public String getFirstName() {
      return firstName;
   }

   public String getLastName() {
      return lastName;
   }

   public String toString() {
      return "Student [ firstName: "+firstName+", lastName: "+ lastName+ " ]";
   }
}

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結果を確認する

次のように javac コンパイラを使用してクラスをコンパイルします-

C:\XStream_WORKSPACE\com\finddevguides\xstream>javac XStreamTester.java

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今、結果を見るためにXStreamTesterを実行します-

C:\XStream_WORKSPACE\com\finddevguides\xstream>java XStreamTester

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次のように出力を確認します-

Student [ firstName: Mahesh, lastName: Parashar ]
Student [ firstName: Suresh, lastName: Kalra ]
Student [ firstName: Ramesh, lastName: Kumar ]
Student [ firstName: Naresh, lastName: Sharma ]
Hello World

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*C：\> XStream_WORKSPACE \ com \ finddevguides \ xstream* フォルダーにあるtest.txtの内容を確認します。

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<?xml version = "1.0" ?>
<object-stream>
   <student>
      <firstName>Mahesh</firstName>
      <lastName>Parashar</lastName>
   </student>

   <student>
      <firstName>Suresh</firstName>
      <lastName>Kalra</lastName>
   </student>

   <student>
      <firstName>Ramesh</firstName>
      <lastName>Kumar</lastName>
   </student>

   <student>
      <firstName>Naresh</firstName>
      <lastName>Sharma</lastName>
   </student>
   <string>Hello World</string>
</object-stream>

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