检查java的class文件版本
直接代码调用对应的方法 checkFilesInDir
import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.util.HashMap; import java.util.Map; import java.util.Scanner; public class CheckClassVersion { public static void main(String[] args) { run(); } private static Map<Integer, String> map = new HashMap<Integer, String>(30); private static boolean showAllClassVersion = false;//false：对比版本时只显示版本错误的class static { JDKVERSION[] values = JDKVERSION.values(); for (JDKVERSION val : values) { map.put(val.getValue(), val.getName()); } } private static void run(){ Scanner scanner = new Scanner(System.in); do{ System.out.println("------输入[class文件路径]或[class所在文件夹路径]------q退出"); String input = scanner.nextLine(); if("q".equalsIgnoreCase(input)){ scanner.close(); break; }else{ System.out.println("==========执行开始=========="); checkFilesInDir(input); System.out.println("==========执行结束=========="); } }while(true); } /** * 显示文件夹下class文件版本号 * @param dirPath */ public static void checkFilesInDir(String dirPath) { checkFilesInDir(dirPath, null); } /** * 检查文件夹下class文件版本号 * @param dirPath * @param jdkVersion 期望class版本号 */ public static void checkFilesInDir(String dirPath, JDKVERSION jdkVersion) { if(jdkVersion!=null){ System.out.println("期望class版本号：" + jdkVersion); } if (dirPath == null) { System.out.println("传入路径为空。"); return; } if (dirPath.endsWith("\\")) { dirPath = dirPath.replaceAll("\\", "/"); } File path = new File(dirPath); if (!path.exists()) { System.out.println(dirPath + "路径不存在。"); return; } if(path.isFile()){ getFileNameAndCheck(path, jdkVersion); } else if(path.isDirectory()){ File[] files = path.listFiles(); if (files != null && files.length > 0) { for (File file : files) { getFileNameAndCheck(file, jdkVersion); } } } } /** * 检查单个class文件版本 * * @param file * @param checkVersion * @return true：版本相同；false：版本不同 */ private static boolean check(String file, JDKVERSION jdkVersion) { if (!file.endsWith(".class")) { return false; } FileInputStream fis = null; byte[] b = null; try { fis = new FileInputStream(file); b = new byte[8]; try { int read = fis.read(b, 0, 8); if (read != 8) { System.out.println(" 文件读取错误"); return false; } int fileVersion = parseFile(b); if(jdkVersion==null){ StringBuffer sb = new StringBuffer(); sb.append(file); sb.append(" 文件版本号:"); sb.append(map.get(fileVersion)); System.out.println(sb.toString()); return false; } if (jdkVersion.getValue() == fileVersion) { if(showAllClassVersion){ StringBuffer sb = new StringBuffer(); sb.append(file); sb.append(" 文件版本号:"); sb.append(map.get(fileVersion)); sb.append(" ------版本正确"); System.out.println(sb.toString()); } return true; }else{ StringBuffer sb = new StringBuffer(); sb.append(file); sb.append(" 文件版本号:"); sb.append(map.get(fileVersion)); sb.append(" ------版本错误"); System.out.println(sb.toString()); return false; } } catch (IOException e) { e.printStackTrace(); } } catch (FileNotFoundException e) { e.printStackTrace(); } finally { if (fis != null) { try { fis.close(); } catch (IOException e) { e.printStackTrace(); } } if (b != null) { b = null; } } return false; } /** * 返回主版本号 * * @param data * @return */ private static int parseFile(byte[] data) { StringBuffer sb = new StringBuffer(); sb.append("魔数(magic):0x"); sb.append(Integer.toHexString(data[0]).substring(6).toUpperCase()); sb.append(Integer.toHexString(data[1]).substring(6).toUpperCase()); sb.append(Integer.toHexString(data[2]).substring(6).toUpperCase()); sb.append(Integer.toHexString(data[3]).substring(6).toUpperCase()); sb.append(" 版本号(version):"); int minor_version = (((int)data[4]) << 8) + data[5];// 次版本号 int major_version = (((int)data[6]) << 8) + data[7];// 主版本号 sb.append(major_version); sb.append("."); sb.append(minor_version); // System.out.println(sb.toString()); return major_version; } private static void getFileNameAndCheck(File file, JDKVERSION jdkVersion) { if (file == null) { return; } if (file.isDirectory()) { File[] files = file.listFiles(); if (files == null || files.length == 0) { return; } for (File f : files) { getFileNameAndCheck(f, jdkVersion); } } else if (file.isFile()) { String fileName = file.getPath(); check(fileName, jdkVersion); } } } /** * jdk版本号 * * @author jinzhm * */ enum JDKVERSION { JDK1(45, "JDK1"), JDK2(46, "JDK2"), JDK3(47, "JDK3"), JDK4(48, "JDK4"), JDK5(49, "JDK5"), JDK6(50, "JDK6"), JDK7( 51, "JDK7"), JDK8(52, "JDK8"), JDK9(53, "JDK9"), JDK10(54, "JDK10"), JDK11(55, "JDK11"), JDK12(56, "JDK12"), JDK13(57, "JDK13"), JDK14(58, "JDK14"), JDK15(59, "JDK15"), JDK16(60, "JDK16"), JDK17(61, "JDK17"); private int value; private String name; private JDKVERSION(int value, String name) { this.value = value; this.name = name; } public int getValue() { return value; } public String getName() { return name; } }
编译两个版本class，瞎搞个bat执行
目录结构
main
-jdk6
-CheckClassVersion.class
-JDKVERSION.class
-jdk8
-CheckClassVersion.class
-JDKVERSION.class
-run.bat
run.bat执行
@echo off @REM 编码 set classpath=%~dp0 set VERSION6="1.6.0_21" for /f "tokens=3" %%g in ('java -version 2^>^&1 ^| findstr /i "version"') do ( @REM @echo Output: %%g set JAVAVER=%%g ) set JAVAVER=%JAVAVER:"=% @REM @echo Output: %JAVAVER% for /f "delims=. tokens=1-3" %%v in ("%JAVAVER%") do ( @REM @echo Major: %%v @REM @echo Minor: %%w @REM @echo Build: %%x set Major=%%v set Minor=%%w set Build=%%x ) set Major=%Major:"=% set Minor=%Minor:"=% set jdkv=%Major%_%Minor% set jdk6=1_6 set jdk8=1_8 echo %jdkv%|findstr %jdk6% >nul &&( goto run1_6) echo %jdkv%|findstr %jdk8% >nul &&( goto run1_8) :run1_6 cd /d %JAVA_HOME%\bin java.exe -classpath %classpath%jdk6\ CheckClassVersion pause > nul exit :run1_8 cd /d %JAVA_HOME%\bin java.exe -classpath %classpath%jdk8\ CheckClassVersion pause > nul exit
