检测JAR包JDK编译版本是否1.5

所在项目的jdk版本是jdk1.5,而开源框架很多都升级到了1.6的版本，为了测试开源框架与现有jdk的兼容性，分享代码如下:

   package org.myframework.jdbc;import java.io.BufferedReader;import java.io.DataInputStream;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.util.zip.ZipEntry;import java.util.zip.ZipFile;import java.util.zip.ZipInputStream;//The first 4 bytes are a magic number, 0xCAFEBABe, to identify a valid class file then the next 2 bytes identify the class format version (major and minor). //Possible major/minor value : //create table m2_lib ( library1 varchar2(100)) ;//select '"'||replace(library1,'\','/')||'",' from m2_lib   ;////select * from    m2_lib  for update;//major  minor Java platform version //45       3           1.0//45       3           1.1//46       0           1.2//47       0           1.3//48       0           1.4//49       0           1.5//50       0           1.6public class ClassVersionChecker { public static void main(String[] args) throws IOException {  // for (int i = 0; i < args.length; i++)  // checkClassVersion(args[i]);  String[] jarsStrings = {         "C:/Users/wanghui/.m2/repository/net/sf/ehcache/ehcache-core/2.4.8/ehcache-core-2.4.8.jar"  };  for (int i = 0; i < jarsStrings.length; i++)   scanJarFileJDK1_5_Version(jarsStrings[i]); } private static void checkClassVersion(String filename) throws IOException {  DataInputStream in = new DataInputStream(new FileInputStream(filename));  int magic = in.readInt();  if (magic != 0xcafebabe) {   System.out.println(filename + " is not a valid class!");   ;  }  int minor = in.readUnsignedShort();  int major = in.readUnsignedShort();  System.out.println(filename + ": " + major + " . " + minor);  in.close(); } private static void checkClassVersion(InputStream in1) throws IOException {  DataInputStream in = new DataInputStream(in1);  int magic = in.readInt();  if (magic != 0xcafebabe) {   System.out.println(in + " is not a valid class!");   ;  }  int minor = in.readUnsignedShort();  int major = in.readUnsignedShort();    System.out.println(": " + major + " . " + minor);  in.close(); }  private static void checkClassJDK1_5_Version(String jar,InputStream in1) throws IOException {  DataInputStream in = new DataInputStream(in1);  int magic = in.readInt();  if (magic != 0xcafebabe) {   System.out.println(in + " is not a valid class!");   ;  }  int minor = in.readUnsignedShort();  int major = in.readUnsignedShort();  if (major >49)  System.out.println(jar+": " + major + " . " + minor);  in.close(); }   public static void scanJarFileJDK1_5_Version(String zipname) {  try {   ZipInputStream zin = new ZipInputStream(     new FileInputStream(zipname));   ZipEntry entry;   while ((entry = zin.getNextEntry()) != null) {    if (entry.getName().endsWith(".class")) {     ZipFile file = new ZipFile(zipname);     InputStream in = file.getInputStream(entry);     checkClassJDK1_5_Version(zipname,in);     break;    }   }   zin.close();  } catch (IOException e) {  } }  public static void scanZipFile(String zipname) {  try {   ZipInputStream zin = new ZipInputStream(     new FileInputStream(zipname));   ZipEntry entry;   while ((entry = zin.getNextEntry()) != null) {    System.out.println(entry.getName());    zin.closeEntry();   }   zin.close();  } catch (IOException e) {  } } public static void scanClassFile(String zipname) {  try {   ZipInputStream zin = new ZipInputStream(     new FileInputStream(zipname));   ZipEntry entry;   while ((entry = zin.getNextEntry()) != null) {    if (entry.getName().endsWith(".class")) {     System.out.println(entry.getName());     ZipFile file = new ZipFile(zipname);     InputStream in = file.getInputStream(entry);     System.out.println(in);     checkClassVersion(in);     break;    }   }   zin.close();  } catch (IOException e) {  } } public static void loadZipFile(String zipname, String name) {  try {   ZipInputStream zin = new ZipInputStream(     new FileInputStream(zipname));   ZipEntry entry;   System.out.println("");   while ((entry = zin.getNextEntry()) != null) {    if (entry.getName().equals(name)) {     BufferedReader in = new BufferedReader(       new InputStreamReader(zin));     String s;     while ((s = in.readLine()) != null)      System.out.println(s + "/n");    }    zin.closeEntry();   }   zin.close();  } catch (IOException e) {  } }}