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Created by magnum on October 09, 2011 19:53:26    Last update: October 09, 2011 19:53:50
#include <stdio.h> #include <stdlib.h> #incl... UNIXguide.net explains this option well: This socket option tells the kernel that even if this port is busy (in the TIME_WAIT state), go ahead and reuse it anyway. If it is busy, but with another state, you will still get an address already in use error. It is useful if your server has been shut down, and then restarted right away while sockets are still active on its port. You should be aware that if any unexpected data comes in, it may confuse your server, but while this is possible, it is not likely. It has been pointed out that "A socket is a 5 tuple (proto, local addr, local port, remote addr, remote port). SO_REUSEADDR just says that you...
Created by Dr. Xi on July 15, 2011 09:25:15    Last update: July 15, 2011 09:25:15
Some methods to search for a substring within a string: To know that a substring indeed exists within a string: boolean found = wholeString.contains(substring); To find where the substring is contained: int index = wholeString.indexOf(substring); If the substring is regex: boolean match = wholeString.matches(".*" + substri... Case insensitive match: convert both whole string and substring to lowercase, then compare. Or, use case insensitive flag for regex. Test code: import java.util.regex.*; public class Stri...
Created by alfa on July 01, 2011 13:16:12    Last update: July 01, 2011 13:16:12
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...
Created by Dr. Xi on June 22, 2011 07:33:45    Last update: June 22, 2011 11:57:54
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......
Created by Dr. Xi on June 22, 2011 09:42:35    Last update: June 22, 2011 11:39:40
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...
Created by Dr. Xi on June 21, 2011 15:41:51    Last update: June 22, 2011 11:33:36
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 | |...
Created by Dr. Xi on June 21, 2011 15:54:00    Last update: June 22, 2011 11:33:09
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 | |...
Created by Dr. Xi on June 22, 2011 07:12:02    Last update: June 22, 2011 11:32:02
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| ...
Created by alfa on June 07, 2011 11:34:26    Last update: June 07, 2011 11:36:37
This is an example that uses dynamic proxies to trace method calls (in logging) and print out elapsed times for them. Because dynamic proxies can only be generated for interfaces, the service classes must be implemented with interface-implementation pairs. Create services A and B. A.java : public interface A { public void service1()... AImpl.java : import java.util.Random; public class AImpl... B.java : public interface B { public void service1()... BImpl.java : public class BImpl implements B { public vo... The call trace proxy: import java.lang.reflect.*; class TraceProx... The performance proxy: import java.lang.reflect.*; class Performan... The service factory: import java.lang.reflect.*; public class Se... The test class: public class Test { public static void main... The output: Entering AImpl.service1 Entering BImpl.service1... The above example has no information...
Created by alfa on June 03, 2011 09:41:03    Last update: June 03, 2011 09:41:03
Dynamic proxy can be used to eliminate the need to stub out unused interface methods. This is an example for a simple SAX content handler for XML parsing. The org.xml.sax.ContentHandler interface requires 11 methods be implemented but we only need three: import java.io.IOException; import java.util.Ar... With a dynamic proxy, we don't need the empty blocks for the unused methods: import java.io.IOException; import java.util.Ar... Equivalently (with anonymous inner class): import java.io.IOException; import java.util.Ar... demo.xml : <breakfast-menu> <food> <name>Belgian W...
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