This is a simple doclet that prints all public methods and their parameter names and types. Code import com.sun.javadoc.*; public class List... Compile javac -cp $JAVA_HOME/lib/tools.jar:. ListMethodsDo... Use javadoc -doclet ListMethodsDoclet -sourcepath /pat...

You should drop the generics notation when looking up a method by signature: import java.util.*; import java.lang.reflect.Me... In fact, Class.forName("java.util.List<java.lang.String>") fails with ClassNotFoundException ! However, all information about parameterized types are not lost at runtime. The Java reflection API does provide these methods to get information about parameterized types at runtime: Method.getGenericExceptionTypes Method.getGenericParameterTypes Method.getGenericReturnType for which the non-generic counterparts are: Method.getExceptionTypes Method.getParameterTypes Method.getReturnType

Parameterized types are considered different at compile time but not at runtime. This program fails compilation because List<Foo> is not the same as List<Bar> : import java.util.ArrayList; import java.util.Li... Error: $ javac SameErasure.java SameErasure.java:8: do... This also fails because List<Foo> and List<Bar> are considered the same: import java.util.ArrayList; import java.util.Li... Error: $ javac SameErasure.java SameErasure.java:11: n...

There's no such thing as an immutable byte array in Java. What we are trying to achieve here is to protect the byte array inside the object from which it is being returned. We want to caller to have the contents of the byte array, but not be able to change the contents inside the object. The trick is to return a copy instead of the internal reference: public class ReturnByteArray { public stati...

Demo code for CSV parsing with OpenCSV . Java code: import java.io.*; import au.com.bytecode.opencs... Test with a simple CSV file: psmith01,CLASS2B,Peter Smith 1,YEAR2,1,N,ADVANCED,... The parser worked correctly: Line 1 has 11 values: |psmith01| |CLASS2B|... Test with a more complicated CSV file: "psmith01 abc", "CLASS2B " , " Peter... Result: Line 1 has 4 values: |psmith01 abc| |CLASS... The parser: Escaped quote and backslash correctly Ignored spaces before the quotation mark - sometimes (see below) Counted spaces after the right quotation mark till the comma as content, including the right quotation mark (bug). Ignored improperly quoted item - silently (third line) Indeed, the OpenCSV parser has a problem with spaces: Input: "Smith, Jack", "210-345-8888" "Smith, J... Result: Line 1 has 2 values: | Smith, Jack| |210-3......

Demo code for CSV parsing with Skife CSV . Java code: import java.io.*; import java.util.*; import... Test with a simple CSV file: psmith01,CLASS2B,Peter Smith 1,YEAR2,1,N,ADVANCED,... The parser worked correctly: Line 1 has 11 values: |psmith01| |CLASS2B|... Test with a more complicated CSV file: "psmith01 abc", "CLASS2B " , " Peter... Result: Line 1 has 4 values: |psmith01 abc| | CLAS... The parser worked correctly. But notice that it counts the spaces outside of the quotes significant, and doing so consistently. One more test for spaces: "Smith, Jack" , "210-345-8888" "Smith, Jack"... Result: Line 1 has 2 values: | Smith, Jack | | 210... Add a new line in item two: "One", "Two ", "Three" Result: Line 1 has 2 values: |One| | Two| L...

Demo code for CSV parsing with Apache Commons CSV parser . Java code: import java.io.*; import org.apache.commons.csv... Test with a simple CSV file: psmith01,CLASS2B,Peter Smith 1,YEAR2,1,N,ADVANCED,... Result: Line 1 has 11 values: |psmith01| |CLASS2B|... The parser worked correctly. Test with a more complicated CSV file: "psmith01 abc", "CLASS2B " , " Peter... Result: Line 1 has 4 values: |psmith01 abc| |CLASS... The third line is invalid input, but throwing a Java IOException is a bit grave. Also, the parser is not able to escape a backslash. Add a new line in item two: "One", "Two ", "Three" Result: Line 2 has 3 values: |One| |Two | |...

Demo code for CSV parsing with SuperCSV parser . Java code: import java.io.*; import java.util.List; imp... Test with a simple CSV file: psmith01,CLASS2B,Peter Smith 1,YEAR2,1,N,ADVANCED,... The parser worked correctly: Line 1 has 11 values: |psmith01| |CLASS2B|... Test with a more complicated CSV file: "psmith01 abc", "CLASS2B " , " Peter... The parser messed up on all three lines: Line 1 has 5 values: |psmith01 abc| |CLASS... Using two lines input: "psmith01 abc", "CLASS2B " , " Peter... It generates an exception: Line 1 has 5 values: |psmith01 abc| |CLASS... Add a new line in item two: "One", "Two ", "Three" Result: Line 2 has 3 values: |One| |Two | |...

Demo code for CSV parsing with OstermillerUtils . Java code: import java.io.*; import java.util.List; imp... Test with a simple CSV file: psmith01,CLASS2B,Peter Smith 1,YEAR2,1,N,ADVANCED,... The parser worked correctly: Line 1 has 11 values: |psmith01| |CLASS2B|... Test with a more complicated CSV file: "psmith01 abc", "CLASS2B " , " Peter... The parser messed up on all three lines: Line 1 has 6 values: |psmith01 abc| | "CLA... Putting a space before the first quote: "Smith, Jack","210-345-8888" It dismissed the quotes: Line 1 has 3 values: | "Smith| | Jack"| ... Add a new line in item two: "One", "Two ", "Three" Result: Line 1 has 2 values: |One| | "Two| ...

This example shows how a service implementation can be loaded with a URLClassLoader . The files. HelloService.java : public interface HelloService { public void... HelloServiceImpl.java : public class HelloServiceImpl implements HelloServ... ServiceFactory.java uses URLClassLoader to load the service implementation: import java.io.*; import java.net.*; pub... Test.java : import java.io.*; import java.net.*; pub... Create a runnable client jar: C:\>jar -cfe client.jar Test Test.class ServiceFac... Create a service jar: jar -cf service.jar HelloServiceImpl.class Test: C:\>java -jar client.jar Class Loader: java.net... Extra Note: : JDK7 added a method URLClassLoader.close() , so that a URLClassLoader can be discarded, and a new one created to load a new implementation.