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Created by alfa on June 02, 2011 13:04:18    Last update: June 02, 2011 13:04:18
Some javap usage examples. Start from HelloWorld.java : @Deprecated public class HelloWorld { pu... javap -c HelloWorld outputs: Compiled from "HelloWorld.java" public class He... javap -v HelloWorld outputs ( -v for verbose mode): Compiled from "HelloWorld.java" public class He... The output consists of: " Compiled from... " header Class attributes. For the HelloWorld example, there are two: SourceFile and Deprecated . Minor and major class file version Constant pool Disassembled code LineNumberTable for debugging purposes. javap by default only prints package/protected/public members. To display all members including private, use the -p switch. javap -v -p HelloWorld
Created by Dr. Xi on January 14, 2010 00:28:27    Last update: March 30, 2011 15:37:44
A task that a Java developer does so frequently is to find out where a certain class can be found - to resolve compilation errors, classpath issues, or version conflicts of the same class introduced by multiple class loaders. A long while back I wrote a simple Perl script to perform the task. Later I was informed that there are Swing based Jar Browser and Jars Browser . Then, there are a couple of shell one-liners: # one liner 1 find -name "*.jar" -print0 | xarg... But all of them share the same problem: if a class is in a jar nested in another jar, it cannot be found. Such is the case for a class inside a jar under the WEB-INF/lib directory of a...
Created by voodoo on July 21, 2010 16:10:47    Last update: July 21, 2010 16:10:47
Google news RSS does not like curl: C:\> curl --dump-header - -o NUL http://news.googl... Switch the agent to HotJava with the -A option: C:\> curl -A "HotJava/1.1.2 FCS" --dump-header - -...
Created by Dr. Xi on June 19, 2010 04:34:01    Last update: June 19, 2010 04:39:13
Java SE 6 contains built-in utilities to generate XML signatures. This is an example that generates XML signatures using a Java keystore. It has options to generate signature for the whole document, for an element with a specific ID, or for elements matched by an XPATH expression. The XML document used to test is taken from Getting Started with XML Security : <?xml version="1.0"?> <PatientRecord> ... This is the Java code: import java.io.FileInputStream; import java.io.... However, it looks like the XPATH transform is not working. The digest generated with XPATH filter is exactly the same as that without it (i.e., the whole document)! Another reference: Programming With the Java XML Digital Signature API
Created by Dr. Xi on January 07, 2010 23:40:28    Last update: February 09, 2010 03:24:35
This is a utility to generate SQL insert statements for Oracle for one table, or a set of tables. It doesn't cover all possibilities but should be good enough for most cases. import java.io.*; import java.sql.*; import ... To generate insert statements for multiple tables, simply put the table names in a file, one per line, and use the -f switch.
Created by Dr. Xi on November 19, 2008 00:22:27    Last update: January 07, 2010 23:00:36
There is a open source project named [ini4j] for processing Windows .ini configuration files. However, I found it an overkill for my purposes. So here is my simple implementation of a .ini parser. It mimics the standard java.util.Properties class with enhancements to get and set properties by section name. There are only a few simple rules: Leading and trailing spaces are trimmed from section names, property names and property values. Section names are enclosed between [ and ] . Properties following a section header belong to that section Properties defined before the appearance of any section headers are considered global properties and should be set and get with no section names. You can use either equal sign ( = ) or colon ( : )...