Gzip压缩文件和压缩字符串，web接口应用
1.压缩文件
package com.example.core.mydemo.gzip;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
/**
* 压缩文件
*/
public class GzipUtil {
public static void compressFile(String sourceFile, String compressedFile) {
try {
FileInputStream fis = new FileInputStream(sourceFile);
FileOutputStream fos = new FileOutputStream(compressedFile);
GZIPOutputStream gzos = new GZIPOutputStream(fos);
byte[] buffer = new byte[1024];
int len;
while ((len = fis.read(buffer)) != -1) {
gzos.write(buffer, 0, len);
}
gzos.finish();
gzos.close();
fos.close();
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void decompressFile(String compressedFile, String decompressedFile) {
try {
FileInputStream fis = new FileInputStream(compressedFile);
FileOutputStream fos = new FileOutputStream(decompressedFile);
GZIPInputStream gzis = new GZIPInputStream(fis);
byte[] buffer = new byte[1024];
int len;
while ((len = gzis.read(buffer)) != -1) {
fos.write(buffer, 0, len);
}
gzis.close();
fos.close();
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
package com.example.core.mydemo.gzip;
public class GzipUtilExample {
public static void main(String[] args) {
// 压缩文件
String sourceFile = "F:\\scooterOrderCommon241021.log";
String compressedFile = "F:\\compressed2.gz";
GzipUtil.compressFile(sourceFile, compressedFile);
// 解压缩文件
String decompressedFile = "F:\\decompressed2.txt";
GzipUtil.decompressFile(compressedFile, decompressedFile);
}
}
2.压缩字符串
package com.example.core.mydemo.gzip;
import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
/**
* gzip字符串压缩的使用
* 使用gzip对字符串进行压缩可以帮助我们在网络传输、文件压缩等场景中减小数据体积，提高传输效率。在实际应用中，我们可以将压缩后的字节数组进行传输或保存到文件中，然后在需要时解压缩并恢复原始字符串。
*
* output:
Compressed string size before: 200
Compressed string size after: 72
byte转字符串(字节大小): 146
byte转字符串= �H����Q(��,V �D�����⒢̼t���"�������܂������<=�A� �����
解压缩字符串=java.io.ByteArrayInputStream@65b3120a
compressed addr=[B@6f539caf
compressed2 addr=[B@79fc0f2f
解压缩字符串2=Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.
res=abcd
*/
public class GzipHelper {
/**
* 压缩方法
* @param input
* @return
* @throws IOException
*/
public static byte[] compressString(String input) throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
GZIPOutputStream gzip = new GZIPOutputStream(bos);
gzip.write(input.getBytes());
gzip.flush();
gzip.close();
return bos.toByteArray();
}
private static StringBuffer unCompressed(byte[] compressed2) throws IOException {
/**
* 解压缩 - 正解
*/
InputStream in = new ByteArrayInputStream(compressed2);
GZIPInputStream gzin = new GZIPInputStream(in);
BufferedReader reader = new BufferedReader(new InputStreamReader(gzin,"UTF-8"));
String line;
StringBuffer sb = new StringBuffer();
while ((line = reader.readLine()) != null) {
sb.append(line);
}
reader.close();
return sb;
}
public static void main(String[] args) throws IOException {
String input = "Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.Hello, this is a test string for gzip compression.";
System.out.println("Compressed string size before: " + input.getBytes().length);
byte[] compressed = compressString(input);
System.out.println("Compressed string size after: " + compressed.length);
//byte转字符串 >> 输出错误 不能通过这种方式转字符串，需要解压缩的方式来处理。
String ss = new String(compressed, StandardCharsets.UTF_8);
System.out.println("byte转字符串(字节大小): " + ss.getBytes().length);
System.out.println("byte转字符串=" + ss); //输出错误
// byte[] compressed2 = compressed; //会报错：Exception in thread "main" java.util.zip.ZipException: Not in GZIP format
//需要克隆对象,使用同一个对象会报错。 解决以上报错
byte[] compressed2 = compressed.clone();
//压缩接口传输
//gzip压缩的逆运算
ByteArrayInputStream ios = new ByteArrayInputStream(compressed);
GZIPInputStream gzip = new GZIPInputStream(ios);
gzip.read(compressed);
gzip.close();
String ss2 = ios.toString();
ios.close();
System.out.println("解压缩字符串=" + ss2);
//Exception in thread "main" java.util.zip.ZipException: Not in GZIP format
/**
* 报错："Not in GZIP format" 通常出现在处理压缩文件时，尤其是在解压GZIP格式的文件时。这个错误表明你尝试解压的文件并不是有效的GZIP格式，可能是因为文件已损坏、不完整或者根本不是GZIP压缩过的。
* 打印出来是2个地址
*/
System.out.println("compressed addr=" + compressed.toString());
System.out.println("compressed2 addr=" + compressed2.toString());
StringBuffer sb = unCompressed(compressed2);
System.out.println("解压缩字符串2=" + sb);
//普通字符串与byte转换，以上是gzip压缩的字符串与byte转换。
String str = "abcd";
byte[] bs = str.getBytes();
String res = new String(bs,"UTF-8");
System.out.println("res=" + res);
}
}
3.web应用demo
import com.test.commons.utils.GsonUtils;
import com.test.commons.web.ErrorCode;
import com.test.insurancedock.service.EhCacheService;
import com.test.insurancedock.vo.req.UserVo;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
@RestController
@RequestMapping("/gzip")
@lombok.extern.slf4j.Slf4j
public class GzipController {
@Autowired
private EhCacheService ehCacheService;
private static final String ENCODING_UTF8 = "UTF-8";
protected static ObjectMapper mapper = new ObjectMapper();
/**
* 方法返回类型：void
* @param request
* @param response
*/
@PostMapping("/saveUser")
public void saveUser(HttpServletRequest request, HttpServletResponse response) {
BufferedReader reader = null;
try {
long start = System.currentTimeMillis();
log.info("添加开始:" + start);
GZIPInputStream gzipIn = new GZIPInputStream(request.getInputStream());
reader = new BufferedReader(new InputStreamReader(gzipIn,"UTF-8"));
String reqContent = reader.readLine();
UserVo userVo = null;
if(StringUtils.hasText(reqContent)){
userVo = mapper.readValue(reqContent,UserVo.class);
}
log.info("接收到的参数值:" + GsonUtils.toJson(userVo));
String res = ehCacheService.updateUser(userVo.getId(),userVo.getName());
System.out.println("添加成功的记录=" + res);
long end = System.currentTimeMillis();
log.info("添加结束:" + end);
log.info("添加耗时：" + (end - start));
writeResponse(response, "json串返回成功");
}catch (Exception e) {
e.printStackTrace();
}finally{
if(reader != null){
try {
reader.close();
} catch (Exception e) {
log.error("",e);
}
}
}
writeResponse(response, "json串返回失败");
}
protected void writeResponse(HttpServletResponse response, Object outJB){
// response.setContentType("text/html; charset=utf-8");
response.setContentType("application/json; charset=utf-8");
//response.setContentType("text/json; charset=utf-8");
response.setCharacterEncoding(ENCODING_UTF8);
response.setHeader("Content-Encoding", "gzip");
GZIPOutputStream out = null;
//byte[] jsonOut = null;
log.info("response start.");
String jsonOut = null;
try {
jsonOut = mapper.writeValueAsString(outJB);
out = new GZIPOutputStream(response.getOutputStream());
out.write(jsonOut.getBytes(ENCODING_UTF8));
out.flush();
} catch (Exception e) {
log.error("output error",e);
} finally{
if(out != null){
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
//单元测试类：
package com.test.insurancedock;
import org.junit.Test;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
public class GzipTest {
private static final String reqUrl = "http://localhost:1340/";
@Test
public void testGzip() {
String url = "gzip/saveUser";
// 获取TN码
String strReq = "{\"id\":\"10\",\"name\":\"zhangliao\"}";
try {
String result = appPost(strReq, reqUrl + url);
System.err.println("接口调用返回结果：" + result);
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* @param str json数据格式
* @param reqUrl
*/
public static String appPost(String str, String reqUrl) throws Exception{
//发送数据
HttpURLConnection conn = null;
StringBuffer sb = new StringBuffer();
try {
URL url = new URL(reqUrl);
conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setUseCaches(false);
conn.setInstanceFollowRedirects(false);//是否自动处理重定向
conn.setRequestMethod("POST");
conn.setRequestProperty("User-Agent", "no");
conn.setRequestProperty("Content-Type", "application/json; charset=utf-8");
conn.connect();
GZIPOutputStream out = new GZIPOutputStream(conn.getOutputStream());
byte[] reqContent = str.getBytes();
System.out.println("testPost发送内容："+new String(reqContent,"UTF-8"));
out.write(reqContent);
out.flush();
out.close();
//接收返回数据
InputStream in = conn.getInputStream();
GZIPInputStream gzin = new GZIPInputStream(in);
BufferedReader reader = new BufferedReader(new InputStreamReader(gzin,"UTF-8"));
String line;
while ((line = reader.readLine()) != null) {
sb.append(line);
}
reader.close();
return sb.toString();
} catch (Exception e) {
e.printStackTrace();
} finally{
if(conn != null){
conn.disconnect();
}
}
return sb.toString();
}
}
打印输出：
testPost发送内容：{"id":"10","name":"zhangliao"}
接口调用返回结果："json串返回成功"