java 内存快照生成 java创建内存文件

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技术博客领航者 2023-07-17 15:40:40

文章标签 java 内存快照生成 java 内存中创建文件 java System Java 文章分类 Java 后端开发

===============>>#1 票数：208 已采纳

看这个例子：

StringBuilder sb = new StringBuilder();
sb.append("Test String");
File f = new File("d:\\test.zip");
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(f));
ZipEntry e = new ZipEntry("mytext.txt");
out.putNextEntry(e);
byte[] data = sb.toString().getBytes();
out.write(data, 0, data.length);
out.closeEntry();
out.close();

这将在D:的根目录中创建一个名为test.zip的zip文件，其中将包含一个名为mytext.txt文件。当然，您可以添加更多的zip条目，还可以指定一个子目录，如下所示：

ZipEntry e = new ZipEntry("folderName/mytext.txt");

您可以在此处找到有关Java压缩的更多信息。

===============>>#2 票数：132

Java 7内置了ZipFileSystem，可用于从zip文件创建，写入和读取文件。

Map env = new HashMap<>();
// Create the zip file if it doesn't exist
env.put("create", "true");
URI uri = URI.create("jar:file:/codeSamples/zipfs/zipfstest.zip");
try (FileSystem zipfs = FileSystems.newFileSystem(uri, env)) {
Path externalTxtFile = Paths.get("/codeSamples/zipfs/SomeTextFile.txt");
Path pathInZipfile = zipfs.getPath("/SomeTextFile.txt");
// Copy a file into the zip file
Files.copy(externalTxtFile, pathInZipfile, StandardCopyOption.REPLACE_EXISTING);
}

===============>>#3 票数：33

要编写ZIP文件，请使用ZipOutputStream。对于要放入ZIP文件中的每个条目，创建一个ZipEntry对象。您将文件名传递给ZipEntry构造函数；它设置其他参数，例如文件日期和解压缩方法。您可以根据需要覆盖这些设置。然后，您调用ZipOutputStream的putNextEntry方法以开始编写新文件。将文件数据发送到ZIP流。完成后，调用closeEntry。对要存储的所有文件重复此操作。这是一个代码框架：

FileOutputStream fout = new FileOutputStream("test.zip");
ZipOutputStream zout = new ZipOutputStream(fout);
for all files
{
ZipEntry ze = new ZipEntry(filename);
zout.putNextEntry(ze);
send data to zout;
zout.closeEntry();
}
zout.close();

===============>>#4 票数：17

这是一个压缩整个目录 (包括子文件和子目录)的示例代码，它使用Java NIO的walk文件树功能。

import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.file.*;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
public class ZipCompress {
public static void compress(String dirPath) {
final Path sourceDir = Paths.get(dirPath);
String zipFileName = dirPath.concat(".zip");
try {
final ZipOutputStream outputStream = new ZipOutputStream(new FileOutputStream(zipFileName));
Files.walkFileTree(sourceDir, new SimpleFileVisitor() {
@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attributes) {
try {
Path targetFile = sourceDir.relativize(file);
outputStream.putNextEntry(new ZipEntry(targetFile.toString()));
byte[] bytes = Files.readAllBytes(file);
outputStream.write(bytes, 0, bytes.length);
outputStream.closeEntry();
} catch (IOException e) {
e.printStackTrace();
}
return FileVisitResult.CONTINUE;
}
});
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

要使用此功能，只需致电

ZipCompress.compress("target/directoryToCompress");

然后您将获得一个zip文件目录ToCompress.zip

===============>>#5 票数：3

public static void main(String args[])
{
omtZip("res/", "omt.zip");
}
public static void omtZip(String path,String outputFile)
{
final int BUFFER = 2048;
boolean isEntry = false;
ArrayList directoryList = new ArrayList();
File f = new File(path);
if(f.exists())
{
try {
FileOutputStream fos = new FileOutputStream(outputFile);
ZipOutputStream zos = new ZipOutputStream(new BufferedOutputStream(fos));
byte data[] = new byte[BUFFER];
if(f.isDirectory())
{
//This is Directory
do{
String directoryName = "";
if(directoryList.size() > 0)
{
directoryName = directoryList.get(0);
System.out.println("Directory Name At 0 :"+directoryName);
}
String fullPath = path+directoryName;
File fileList = null;
if(directoryList.size() == 0)
{
//Main path (Root Directory)
fileList = f;
}else
{
//Child Directory
fileList = new File(fullPath);
}
String[] filesName = fileList.list();
int totalFiles = filesName.length;
for(int i = 0 ; i < totalFiles ; i++)
{
String name = filesName[i];
File filesOrDir = new File(fullPath+name);
if(filesOrDir.isDirectory())
{
System.out.println("New Directory Entry :"+directoryName+name+"/");
ZipEntry entry = new ZipEntry(directoryName+name+"/");
zos.putNextEntry(entry);
isEntry = true;
directoryList.add(directoryName+name+"/");
}else
{
System.out.println("New File Entry :"+directoryName+name);
ZipEntry entry = new ZipEntry(directoryName+name);
zos.putNextEntry(entry);
isEntry = true;
FileInputStream fileInputStream = new FileInputStream(filesOrDir);
BufferedInputStream bufferedInputStream = new BufferedInputStream(fileInputStream, BUFFER);
int size = -1;
while( (size = bufferedInputStream.read(data, 0, BUFFER)) != -1 )
{
zos.write(data, 0, size);
}
bufferedInputStream.close();
}
}
if(directoryList.size() > 0 && directoryName.trim().length() > 0)
{
System.out.println("Directory removed :"+directoryName);
directoryList.remove(0);
}
}while(directoryList.size() > 0);
}else
{
//This is File
//Zip this file
System.out.println("Zip this file :"+f.getPath());
FileInputStream fis = new FileInputStream(f);
BufferedInputStream bis = new BufferedInputStream(fis,BUFFER);
ZipEntry entry = new ZipEntry(f.getName());
zos.putNextEntry(entry);
isEntry = true;
int size = -1 ;
while(( size = bis.read(data,0,BUFFER)) != -1)
{
zos.write(data, 0, size);
}
}
//CHECK IS THERE ANY ENTRY IN ZIP ? ----START
if(isEntry)
{
zos.close();
}else
{
zos = null;
System.out.println("No Entry Found in Zip");
}
//CHECK IS THERE ANY ENTRY IN ZIP ? ----START
}catch(Exception e)
{
e.printStackTrace();
}
}else
{
System.out.println("File or Directory not found");
}
}
}

===============>>#6 票数：2

Zip4j完全使用Java代码，而没有任何本机代码的支持，因此它更适合我。 Zip4j提供以下功能：

创建，添加，提取，更新，从Zip文件中删除文件

读/写受密码保护的Zip文件

支持AES 128/256加密

支持标准邮编加密

支持Zip64格式

支持存储(无压缩)和压缩压缩方法

从Split Zip文件创建或提取文件(例如：z01，z02，…zip)

支持Unicode文件名

进度监控器

CreatePasswordProtectedZipExample.java
import java.io.File;
import java.util.ArrayList;
import net.lingala.zip4j.core.ZipFile;
import net.lingala.zip4j.exception.ZipException;
import net.lingala.zip4j.model.ZipParameters;
import net.lingala.zip4j.util.Zip4jConstants;
public class CreatePasswordProtectedZipExample
{
public static void main(String[] args)
{
try {
//This is name and path of zip file to be created
ZipFile zipFile = new ZipFile("C:/temp/test.zip");
//Add files to be archived into zip file
ArrayList filesToAdd = new ArrayList();
filesToAdd.add(new File("C:/temp/test1.txt"));
filesToAdd.add(new File("C:/temp/test2.txt"));
//Initiate Zip Parameters which define various properties
ZipParameters parameters = new ZipParameters();
parameters.setCompressionMethod(Zip4jConstants.COMP_DEFLATE); // set compression method to deflate compression
//DEFLATE_LEVEL_FASTEST - Lowest compression level but higher speed of compression
//DEFLATE_LEVEL_FAST - Low compression level but higher speed of compression
//DEFLATE_LEVEL_NORMAL - Optimal balance between compression level/speed
//DEFLATE_LEVEL_MAXIMUM - High compression level with a compromise of speed
//DEFLATE_LEVEL_ULTRA - Highest compression level but low speed
parameters.setCompressionLevel(Zip4jConstants.DEFLATE_LEVEL_NORMAL);
//Set the encryption flag to true
parameters.setEncryptFiles(true);
//Set the encryption method to AES Zip Encryption
parameters.setEncryptionMethod(Zip4jConstants.ENC_METHOD_AES);
//AES_STRENGTH_128 - For both encryption and decryption
//AES_STRENGTH_192 - For decryption only
//AES_STRENGTH_256 - For both encryption and decryption
//Key strength 192 cannot be used for encryption. But if a zip file already has a
//file encrypted with key strength of 192, then Zip4j can decrypt this file
parameters.setAesKeyStrength(Zip4jConstants.AES_STRENGTH_256);
//Set password
parameters.setPassword("howtodoinjava");
//Now add files to the zip file
zipFile.addFiles(filesToAdd, parameters);
}
catch (ZipException e)
{
e.printStackTrace();
}
}
}

===============>>#7 票数：2

Spring Boot控制器，将文件压缩到一个目录中，并且可以下载。

@RequestMapping(value = "/files.zip")
@ResponseBody
byte[] filesZip() throws IOException {
File dir = new File("./");
File[] filesArray = dir.listFiles();
if (filesArray == null || filesArray.length == 0)
System.out.println(dir.getAbsolutePath() + " have no file!");
ByteArrayOutputStream bo = new ByteArrayOutputStream();
ZipOutputStream zipOut= new ZipOutputStream(bo);
for(File xlsFile:filesArray){
if(!xlsFile.isFile())continue;
ZipEntry zipEntry = new ZipEntry(xlsFile.getName());
zipOut.putNextEntry(zipEntry);
zipOut.write(IOUtils.toByteArray(new FileInputStream(xlsFile)));
zipOut.closeEntry();
}
zipOut.close();
return bo.toByteArray();
}
===============>>#8 票数：2
这是从源文件创建zip文件的方式：
String srcFilename = "C:/myfile.txt";
String zipFile = "C:/myfile.zip";
try {
byte[] buffer = new byte[1024];
FileOutputStream fos = new FileOutputStream(zipFile);
ZipOutputStream zos = new ZipOutputStream(fos);
File srcFile = new File(srcFilename);
FileInputStream fis = new FileInputStream(srcFile);
zos.putNextEntry(new ZipEntry(srcFile.getName()));
int length;
while ((length = fis.read(buffer)) > 0) {
zos.write(buffer, 0, length);
}
zos.closeEntry();
fis.close();
zos.close();
}
catch (IOException ioe) {
System.out.println("Error creating zip file" + ioe);
}

===============>>#9 票数：1

单个文件：

String filePath = "/absolute/path/file1.txt";
String zipPath = "/absolute/path/output.zip";
try (ZipOutputStream zipOut = new ZipOutputStream(new FileOutputStream(zipPath))) {
File fileToZip = new File(filePath);
zipOut.putNextEntry(new ZipEntry(fileToZip.getName()));
Files.copy(fileToZip.toPath(), zipOut);
}

多个文件：

List filePaths = Arrays.asList("/absolute/path/file1.txt", "/absolute/path/file2.txt");
String zipPath = "/absolute/path/output.zip";
try (ZipOutputStream zipOut = new ZipOutputStream(new FileOutputStream(zipPath))) {
for (String filePath : filePaths) {
File fileToZip = new File(filePath);
zipOut.putNextEntry(new ZipEntry(fileToZip.getName()));
Files.copy(fileToZip.toPath(), zipOut);
}
}

===============>>#10 票数：1

您必须主要创建两个功能。第一个是writeToZipFile()，第二个是createZipfileForOutPut ....然后调用createZipfileForOutPut('。zip文件名')...…

public static void writeToZipFile(String path, ZipOutputStream zipStream)
throws FileNotFoundException, IOException {
System.out.println("Writing file : '" + path + "' to zip file");
File aFile = new File(path);
FileInputStream fis = new FileInputStream(aFile);
ZipEntry zipEntry = new ZipEntry(path);
zipStream.putNextEntry(zipEntry);
byte[] bytes = new byte[1024];
int length;
while ((length = fis.read(bytes)) >= 0) {
zipStream.write(bytes, 0, length);
}
zipStream.closeEntry();
fis.close();
}
public static void createZipfileForOutPut(String filename) {
String home = System.getProperty("user.home");
// File directory = new File(home + "/Documents/" + "AutomationReport");
File directory = new File("AutomationReport");
if (!directory.exists()) {
directory.mkdir();
}
try {
FileOutputStream fos = new FileOutputStream("Path to your destination" + filename + ".zip");
ZipOutputStream zos = new ZipOutputStream(fos);
writeToZipFile("Path to file which you want to compress / zip", zos);
zos.close();
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}

===============>>#11 票数：0

如果要在不使用软件的情况下进行解压缩，最好使用此代码。带有pdf文件的其他代码在手动解压缩时发送错误

byte[] buffer = new byte[1024];
try
{
FileOutputStream fos = new FileOutputStream("123.zip");
ZipOutputStream zos = new ZipOutputStream(fos);
ZipEntry ze= new ZipEntry("file.pdf");
zos.putNextEntry(ze);
FileInputStream in = new FileInputStream("file.pdf");
int len;
while ((len = in.read(buffer)) > 0)
{
zos.write(buffer, 0, len);
}
in.close();
zos.closeEntry();
zos.close();
}
catch(IOException ex)
{
ex.printStackTrace();
}

===============>>#12 票数：0

由于花了我一段时间才弄清楚，所以我认为使用Java 7+ ZipFileSystem发布解决方案会有所帮助

openZip(runFile);
addToZip(filepath); //loop construct;
zipfs.close();
private void openZip(File runFile) throws IOException {
Map env = new HashMap<>();
env.put("create", "true");
env.put("encoding", "UTF-8");
Files.deleteIfExists(runFile.toPath());
zipfs = FileSystems.newFileSystem(URI.create("jar:" + runFile.toURI().toString()), env);
}
private void addToZip(String filename) throws IOException {
Path externalTxtFile = Paths.get(filename).toAbsolutePath();
Path pathInZipfile = zipfs.getPath(filename.substring(filename.lastIndexOf("results"))); //all files to be stored have a common base folder, results/ in my case
if (Files.isDirectory(externalTxtFile)) {
Files.createDirectories(pathInZipfile);
try (DirectoryStream ds = Files.newDirectoryStream(externalTxtFile)) {
for (Path child : ds) {
addToZip(child.normalize().toString()); //recursive call
}
}
} else {
// copy file to zip file
Files.copy(externalTxtFile, pathInZipfile, StandardCopyOption.REPLACE_EXISTING);
}
}

===============>>#13 票数：0

public static void zipFromTxt(String zipFilePath, String txtFilePath) {
Assert.notNull(zipFilePath, "Zip file path is required");
Assert.notNull(txtFilePath, "Txt file path is required");
zipFromTxt(new File(zipFilePath), new File(txtFilePath));
}
public static void zipFromTxt(File zipFile, File txtFile) {
ZipOutputStream out = null;
FileInputStream in = null;
try {
Assert.notNull(zipFile, "Zip file is required");
Assert.notNull(txtFile, "Txt file is required");
out = new ZipOutputStream(new FileOutputStream(zipFile));
in = new FileInputStream(txtFile);
out.putNextEntry(new ZipEntry(txtFile.getName()));
int len;
byte[] buffer = new byte[1024];
while ((len = in.read(buffer)) > 0) {
out.write(buffer, 0, len);
out.flush();
}
} catch (Exception e) {
log.info("Zip from txt occur error,Detail message:{}", e.toString());
} finally {
try {
if (in != null) in.close();
if (out != null) {
out.closeEntry();
out.close();
}
} catch (Exception e) {
log.info("Zip from txt close error,Detail message:{}", e.toString());
}
}
}

===============>>#14 票数：0

给定exportPath和queryResults作为String变量，以下块在exportPath下创建了一个results.zip文件， exportPath queryResults的内容写入到zip内的results.txt文件中。

URI uri = URI.create("jar:file:" + exportPath + "/results.zip");
Map env = Collections.singletonMap("create", "true");
try (FileSystem zipfs = FileSystems.newFileSystem(uri, env)) {
Path filePath = zipfs.getPath("/results.txt");
byte[] fileContent = queryResults.getBytes();
Files.write(filePath, fileContent, StandardOpenOption.CREATE);
}

===============>>#15 票数：0

使用Jeka https://jeka.dev JkPathTree，这非常简单。

Path wholeDirToZip = Paths.get("dir/to/zip");
Path zipFile = Paths.get("file.zip");
JkPathTree.of(wholeDirToZip).zipTo(zipFile);
ask by Ashish Agarwal translate from so

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