Think in Java p40 3.4.1
class letter{
char c;
}
public class passobject {
static void f(letter y){
y.c='z';
}
public static void main(string[] args){
letter x=new letter();
x.c='a';
system.out.println("1:x.c:"+x.c);
f(x);
system.out.println("2:x.c:"+x.c);
}
}
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1. ¼ò½é
2. °²×°
3. log4j»ù±¾¸ÅÄî
3.1. Logger
3.2. Appender
3.2.1. ʹÓÃConsoleAppender
3.2.2. ʹÓÃFileAppender
3.2.3. ʹÓÃWriterAppender
3.3. Layout
3.4. »ù±¾Ê¾Àý
3.4.1. SimpleLayoutºÍFileAppender
3.4.2. HTMLLayoutºÍWriterAppender
3.4.3. PatternLayoutºÍConsoleAppender
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//Example 1 Tst.java£¬no main() method
package com.blogchina.qb2049;
public class Tst
{
static { System.out.println("111111"); }
}
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Exception in thread "main" java.lang.NoSuchMethodError: main
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Calendar time=Calendar.getInstance();
time.clear();
time.set(Calendar.YEAR,year);
time.set(Calendar.MONTH,i-1);//×¢Òâ,Calendar¶ÔÏóĬÈÏÒ»ÔÂΪ0
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