如何在Java中将InputStream转换为File

以下是一些将InputStream转换为File Java示例

1. 手动将InputStream复制到FileOutputStream
2. Apache Commons IO – FileUtils.copyInputStreamToFile
3. Java 1.7 NIO Files.copy

1. FileOutputStream

1.1我们必须将数据从InputStream手动复制到OutputStream 。

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

 
    
    
      commons-io 
     
    
      commons-io 
     
    
      2.6 
     
   

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如果只想将inputStream保存到某个文件中，请尝试使用Java 1.7 NIO Files.copy

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.旧时光

4.1在过去的Java 1.7之前，我们必须手动关闭所有资源。

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.将文件转换为InputStream

这很容易：

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

注意
您可能对此String的InputStream感兴趣

参考文献

• 文件JavaDocs
• 如何在Java中将InputStream转换为String
• Apache Commons IO

翻译自: https://mkyong.com/java/how-to-convert-inputstream-to-file-in-java/