如何通过java程序找到jar的最新jar版本？

Question

在我的项目中有40到50个jar文件可用，每次都需要很多时间才能找到每个jar的最新版本。你可以任何一个帮我为这个写一个java程序？

Answer 1

您可能只想使用maven：http://maven.apache.org/ 或其他依赖项管理器，如Ivy。

Answer 2

At the time of ant-build please call this method 
public void ExpungeDuplicates(String filePath) { 
    Map<String,Integer> replaceJarsMap = null; 
    File folder = null; 
    File[] listOfFiles = null; 
    List<String> jarList = new ArrayList<String>(); 
    String files = ""; 
    File deleteFile = null; 
    Iterator<String> mapItr = null; 
    //String extension ="jar"; 
    try { 
      folder = new File(filePath); 
     listOfFiles = folder.listFiles(); 
     for (int i = 0; i < listOfFiles.length; i++) { 
      if (listOfFiles[i].isFile()) { 
       files = listOfFiles[i].getName(); 
       jarList.add(files); 
      } 
     } 
     if (jarList.size() > 0) { 
      replaceJarsMap = PatternClassifier.findDuplicatesOrLowerVersion(jarList); 
      System.err.println("Duplicate/Lower Version - Total Count : "+replaceJarsMap.size()); 
      mapItr = replaceJarsMap.keySet().iterator(); 
      while (mapItr.hasNext()) { 
       String key = mapItr.next(); 
       int repeat = replaceJarsMap.get(key); 
       System.out.println(key +" : "+repeat); 
       for (int i = 0; i <repeat; i++) { 
        deleteFile = new File(filePath + System.getProperty ("file.separator")+key); 
        try{ 
        if (deleteFile != null && deleteFile.exists()){ 
         if(deleteFile.delete()){ 
          System.err.println(key +" deleted"); 
         } 
        } 
        }catch (Exception e) { 
        } 
       } 
      } 
     } 

} catch (Exception e) { 
    // TODO: handle exception 
} 
} 

您只需要将您的Lib的路径给这个函数。此方法将查找所有重复或较低版本的文件。 下面给出了至关重要的功能......它从您提供的文件列表中找出重复项。

public static Map<String,Integer> findDuplicatesOrLowerVersion(List<String> fileNameList) { 
    List<String> oldJarList = new ArrayList<String>(); 
    String cmprTemp[] = null; 
    boolean match = false; 
    String regex = "",regexFileType = "",verInfo1 = "",verInfo2 = "",compareName = "",tempCompareName = "",tempJarName =""; 
    Map<String,Integer> duplicateEntryMap = new HashMap<String, Integer>(); 
    int count = 0; 
    Collections.sort(fileNameList, Collections.reverseOrder()); 
    try{ 
     int size = fileNameList.size(); 
     for(int i = 0;i<size;i++){ 
      cmprTemp = fileNameList.get(i).split("[0-9\\._]*"); 
      for(String s : cmprTemp){ 
       compareName += s; 
      } 
      regex = "^"+compareName+"[ajr0-9_\\-\\.]*"; 
      regexFileType = "[0-9a-zA-Z\\-\\._]*\\.jar$"; 
      if(fileNameList.get(i).matches(regexFileType) && !oldJarList.contains(fileNameList.get(i))){ 
       for(int j = i+1 ;j<size;j++){ 
        cmprTemp = fileNameList.get(j).split("[0-9\\._]*"); 
        for(String s : cmprTemp){ 
         tempCompareName += s; 
        } 
        match = (fileNameList.get(j).matches(regexFileType) && tempCompareName.matches(regex)); 
        if(match){ 
          cmprTemp = fileNameList.get(i).split("[a-zA-Z\\-\\._]*"); 
          for(String s : cmprTemp){ 
           verInfo1 += s; 
          } 
          verInfo1 += "000"; 
          cmprTemp = fileNameList.get(j).split("[a-zA-Z\\-\\._]*"); 
          for(String s : cmprTemp){ 
           verInfo2 += s; 
          } 
          verInfo2 += "000"; 
          int length = 0; 
          if(verInfo1.length()>verInfo2.length()){ 
           length = verInfo2.length();       
         }else{ 
          length = verInfo1.length(); 
         } 
         if(Long.parseLong(verInfo1.substring(0,length))>=Long.parseLong(verInfo2.substring(0,length))){ 
          count = 0; 
          if(!oldJarList.contains(fileNameList.get(j))){ 
           oldJarList.add(fileNameList.get(j)); 
           duplicateEntryMap.put(fileNameList.get(j),++count); 
          }else{ 
           count = duplicateEntryMap.get(fileNameList.get(j)); 
           duplicateEntryMap.put(fileNameList.get(j),++count); 
          } 
         }else{ 
          tempJarName = fileNameList.get(i); 
         } 
         match = false;verInfo1 = "";verInfo2 = ""; 
       } 
        tempCompareName = ""; 
       } 
       if(tempJarName!=null && !tempJarName.equals("")){ 
        count = 0; 
        if(!oldJarList.contains(fileNameList.get(i))){ 
         oldJarList.add(fileNameList.get(i)); 
         duplicateEntryMap.put(fileNameList.get(i),++count); 
        }else{ 
         count = dupl icateEntryMap.get(fileNameList.get(i)); 
         duplicateEntryMap.put(fileNameList.get(i),++count); 
        } 
        tempJarName = ""; 
       } 
      } 
      compareName = ""; 
     } 
    }catch (Exception e) { 
     e.printStackTrace(); 
    } 
    return duplicateEntryMap; 
}  

什么findDuplicatesOrLowerVersion（名单fileNameList）函数的任务 - 只要它发现的重复和passting一个映射，其中包含的文件和时间数低版本重复的名字。

Try this. The remaining file exist in the folder should be latest or files with out duplicates.Am using this for finding the oldest files.on the basis of that it will find the old and delete it. 
This am only checking the name..Futher improvement you can made. 

Where PatternClassifier is a class which contains the second method given here.