CODEWITHSUNDEEP
javainputstreamaopjavassistgetresource
Nick Dong
Nick Dong

Reputation: 3736

how to get inputstream from class file existed in other project

I am trying to get inputstream from class file of the other project.

I am using eclipse. The output folder is:

mycurrentproject/WebContent/WEB-INF/classes.

The export library folder is:

mycurrentproject/WebContent/WEB-INF/lib.

When I print "java.class.path", I got this:

D:\apache-tomcat-7.0.42\bin\bootstrap.jar;D:\apache-tomcat-7.0.42\bin\tomcat-juli.jar;

My environment variable of CLASS PATH of WINDOWS system is:

.;%JAVA_HOME%\lib\dt.jar;%JAVA_HOME%\lib\tools.jar;D:\work\workspace\myjar

My code in package action to get resource stream is:

classfilePath = "/cc/Person.class";
InputStream isInputStream = ModifyMethodTest.class.getResourceAsStream(classfilePath);

Package action is outputed in "mycurrentproject/WebContent/WEB-INF/classes". action.jar is exported in "mycurrentproject/WebContent/WEB-INF/lib".

When cc/Person.class in "mycurrentproject/WebContent/WEB-INF/classes", I got right result. When cc/Person.class in "mycurrentproject/WebContent/WEB-INF/lib" or in "D:\work\workspace\myjar". isInputStream got null. I want to get inputstream form a class file in the other project. The class file maybe in a folder or in a jar file in the target project folder. There should be many classes or jar files in that project. How to do that? For now, and for simple, I test my idea as above to put cc/Person.class in "D:\work\workspace\myjar". But It failed either. Any one have similar experience or advices? Thanks.

EDIT:

classfilePath ="file:D:/work/workspace/myjar/cc/Person.class"; 
URL[] urls = new URL[] { new URL(classfilePath) }; 
URLClassLoader ucl = new URLClassLoader(urls); 
InputStream isInputStream = ucl.getResourceAsStream(classfilePath);

Here isInputStream still got null. The parameter of getResourceAsStream() is String name. What could be? Something like relative path? Any references?

EDIT2:

It works with code as follow:

String Path1 = "file:D:/";
String Path2 = "work/workspace/myjar/cc/Person.class";

URL[] urls = new URL[] { new URL(Path1) }; 
URLClassLoader ucl = new URLClassLoader(urls); 
InputStream isInputStream = ucl.getResourceAsStream(Path2);

Upvotes: 1

Views: 1943

Answers (1)

Andrew Thompson
Andrew Thompson

Reputation: 168825

Use an URLClassLoader. Once you've established it, call:

getResourceAsStream("/work/workspace/myjar/cc/Person.class")

For the InputStream.

Upvotes: 1

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