Java中將InputStream轉換為File

以下是一些將InputStream轉換為File Java示例

手動將InputStream復制到FileOutputStream
Apache Commons IO – FileUtils.copyInputStreamToFile
Java 1.7 NIO Files.copy
1. FileOutputStream
1.1我們必須將數據從InputStream手動復制到OutputStream 。

InputStreamToFile.java
package com.mkyong;
 
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
 
public class InputStreamToFile {
 
    private static final String FILE_TO = "d:\\download\\google.txt";
 
    public static void main(String[] args) throws IOException {
 
        URI u = URI.create("https://www.google.com/");
        try (InputStream inputStream = u.toURL().openStream()) {
            File file = new File(FILE_TO);
            copyInputStreamToFile(inputStream, file);
        }
    }
 
    // InputStream -> File
    private static void copyInputStreamToFile(InputStream inputStream, File file) 
        throws IOException {
 
        try (FileOutputStream outputStream = new FileOutputStream(file)) {
 
            int read;
            byte[] bytes = new byte[1024];
 
            while ((read = inputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, read);
            }
 
            // commons-io
            //IOUtils.copy(inputStream, outputStream);
 
        }
 
    }
 
}
2. Apache Commons IO
2.1 FileUtils.copyInputStreamToFile在Apache Commons IO中可用

pom.xml
<dependency>
        <groupId>commons-io</groupId>
        <artifactId>commons-io</artifactId>
        <version>2.6</version>
    </dependency>
InputStreamToFile2.java
package com.mkyong;
 
import org.apache.commons.io.FileUtils;
 
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
 
public class InputStreamToFile2 {
 
    private static final String FILE_TO = "d:\\download\\google.txt";
 
    public static void main(String[] args) throws IOException {
 
        URI u = URI.create("https://www.google.com/");
        try (InputStream inputStream = u.toURL().openStream()) {
 
            File file = new File(FILE_TO);
 
            // commons-io
            FileUtils.copyInputStreamToFile(inputStream, file);
        }
 
    }
 
}
3. Java 1.7 NIO
3.1如果只想將inputStream保存到某個文件中，請嘗試使用Java 1.7 NIO Files.copy

InputStreamToFile3.java
package com.mkyong;
 
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.nio.file.Files;
import java.nio.file.Paths;
 
public class InputStreamToFile3 {
 
    private static final String FILE_TO = "d:\\download\\google.txt";
 
    public static void main(String[] args) throws IOException {
 
        URI u = URI.create("https://www.google.com/");
        try (InputStream inputStream = u.toURL().openStream()) {
 
            //Java 1.7
            Files.copy(inputStream, Paths.get(FILE_TO));
 
        }
 
    }
 
}
4.舊時光
4.1在過去的Java 1.7之前，我們必須手動關閉所有資源。

InputStreamToFile4.java
package com.mkyong;
 
import java.io.*;
 
public class InputStreamToFile4 {
 
    public static void main(String[] args) {
 
        InputStream inputStream = null;
        OutputStream outputStream = null;
 
        try {
            // read this file into InputStream
            inputStream = new FileInputStream("/Users/mkyong/holder.js");
 
            // write the inputStream to a FileOutputStream
            outputStream = new FileOutputStream(new File("/Users/mkyong/holder-new.js"));
 
            int read = 0;
            byte[] bytes = new byte[1024];
 
            while ((read = inputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, read);
            }
 
            System.out.println("Done!");
 
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (outputStream != null) {
                try {
                    outputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
 
            }
        }
    }
 
}
5.將文件轉換為InputStream
這很容易：

File file = new File("d:\\download\\google.txt");
    InputStream inputStream = new FileInputStream(file);