java实现两个文件的拼接

1. 拼接文本文件：利用FileReader和FileWriter类分别读取和写入文件内容，再利用BufferedReader和BufferedWriter类对文件内容进行缓存处理，实现拼接文本文件的操作。以下为示例代码：

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class ConcatenateTextFile {

    public static void main(String[] args) {
        String file1 = "file1.txt";
        String file2 = "file2.txt";
        String output = "output.txt";

        try (BufferedReader br1 = new BufferedReader(new FileReader(file1));
                BufferedReader br2 = new BufferedReader(new FileReader(file2));
                BufferedWriter bw = new BufferedWriter(new FileWriter(output))) {
            String line = null;
            while ((line = br1.readLine()) != null) {
                bw.write(line);
                bw.newLine();
            }
            while ((line = br2.readLine()) != null) {
                bw.write(line);
                bw.newLine();
            }
        } catch (IOException e) {
            System.err.format("IOException: %s%n", e);
        }
    }

}

1. 拼接二进制文件：利用FileInputStream和FileOutputStream类分别读取和写入文件内容，再利用ByteArrayInputStream和ByteArrayOutputStream类对文件内容进行缓存处理，实现拼接二进制文件的操作。以下为示例代码：

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class ConcatenateBinaryFile {

    public static void main(String[] args) {
        String file1 = "file1.bin";
        String file2 = "file2.bin";
        String output = "output.bin";

        try (FileInputStream fis1 = new FileInputStream(file1);
                FileInputStream fis2 = new FileInputStream(file2);
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                FileOutputStream fos = new FileOutputStream(output)) {
            byte[] buffer = new byte[1024];
            int length;
            while ((length = fis1.read(buffer)) != -1) {
                baos.write(buffer, 0, length);
            }
            while ((length = fis2.read(buffer)) != -1) {
                baos.write(buffer, 0, length);
            }
            baos.flush();
            fos.write(baos.toByteArray());
        } catch (IOException e) {
            System.err.format("IOException: %s%n", e);
        }
    }

}

以上两个示例均可直接运行，结果输出到指定的output文件中。