AspectJ HelloWorld程序

下载Aspectj： http://www.eclipse.org/aspectj/downloads.php
配置好PATH和CLASSPATH后，可以试试ajc编译器是否work。

D:\java\aspectjDemo>ajc
{0}

        Usage: <options> <source file | @argfile>..

AspectJ-specific options:
        -inpath <list>      use classes in dirs and jars/zips in <list> as sourc
e
                            (<list> uses platform-specific path delimiter)
        -injars <jarList>   use classes in <jarList> zip files as source
                            (<jarList> uses classpath delimiter)
                            deprecated - use inpath instead.
        -aspectpath <list>  weave aspects in .class files from <list> dirs and j
ars/zip into sources
                            (<list> uses classpath delimiter)
        -outjar <file>      put output classes in zip file <file>
        -outxml             generate META-INF/aop.xml
        -outxmlfile <file>  specify alternate destination output of -outxml
        -argfile <file>     specify line-delimited list of source files
        -showWeaveInfo      display information about weaving
        -incremental        continuously-running compiler, needs -sourceroots
                            (reads stdin: enter to recompile and 'q' to quit)
        -sourceroots <dirs> compile all .aj and .java files in <dirs>
                            (<dirs> uses classpath delimiter)
        -crossrefs          generate .ajsym file into the output directory
        -emacssym           generate .ajesym symbol files for emacs support
        -Xlint              same as '-Xlint:warning'
        -Xlint:<level>      set default level for crosscutting messages
                            (<level> may be ignore, warning, or error)
        -Xlintfile <file>   specify properties file to set per-message levels
                            (cf org/aspectj/weaver/XlintDefault.properties)
        -X                  print help on non-standard options

Standard Eclipse compiler options:
Options enabled by default are prefixed with '+'

Classpath options:
    -cp -classpath <directories and zip/jar files separated by ;>
                       specify location for application classes and sources
    -bootclasspath <directories and zip/jar files separated by ;>
                       specify location for system classes
    -d <dir>           destination directory (if omitted, no directory is create
d)
    -d none            generate no .class files
    -encoding <enc>    specify custom encoding for all sources. Each file/direct
ory can override it
                       when suffixed with '['<enc>']' (e.g. X.java[utf8])

Compliance options:
    -1.3               use 1.3 compliance level (implicit -source 1.3 -target 1.
1)
    -1.4             + use 1.4 compliance level
    -1.5               use 1.5 compliance level
    -1.6               use 1.6 compliance level
    -source <version>  set source level (1.3, 1.4, 1.5 or 1.6)
    -target <version>  set classfile target (1.1 to 1.4)

Warning options:
    -deprecation     + deprecation outside deprecated code
    -nowarn            disable all warnings except xlint or declare warning
    -warn:none         disable all warnings except xlint or declare warning
    -warn:<warnings separated by ,>    enable exactly the listed warnings
    -warn:+<warnings separated by ,>   enable additional warnings
    -warn:-<warnings separated by ,>   disable specific warnings
      allDeprecation       deprecation including inside deprecated code
      allJavadoc           invalid or missing javadoc
      assertIdentifier   + 'assert' used as identifier
      charConcat         + char[] in String concat
      conditionAssign      possible accidental boolean assignment
      constructorName    + method with constructor name
      deprecation        + deprecation outside deprecated code
      emptyBlock           undocumented empty block
      fieldHiding          field hiding another variable
      finally            + finally block not completing normally
      indirectStatic       indirect reference to static member
      intfNonInherited   + interface non-inherited method compatibility
      javadoc              invalid javadoc
      localHiding          local variable hiding another variable
      maskedCatchBlock   + hidden catch block
      nls                  string literal lacking non-nls tag //$NON-NLS-<n>$
      noEffectAssign     + assignment without effect
      pkgDefaultMethod   + attempt to override package-default method
      semicolon            superfluous semicolon
      unqualifiedField     unqualified reference to field
      unusedImport       + unused import declaration
      unusedLocal          unread local variable
      unusedPrivate        unused private member declaration
      unusedThrown         unused declared thrown exception
      uselessTypeCheck     unnecessary cast/instanceof operation
      specialParamHiding   constructor or setter parameter hiding another field
      staticReceiver     + non-static reference to static member
      syntheticAccess      synthetic access for innerclass
      tasks(<tags separated by |>) tasks identified by tags inside comments

Debug options:
    -g[:lines,vars,source] custom debug info
    -g:lines,source  + both lines table and source debug info
    -g                 all debug info
    -g:none            no debug info
    -preserveAllLocals preserve unused local vars for debug purpose

Advanced options:
    -log <file>        log to a file
    -proceedOnError    do not stop at first error, dumping class files with prob
lem methods
    -verbose           enable verbose output
    -referenceInfo     compute reference info
    -progress          show progress (only in -log mode)
    -time              display speed information
    -noExit            do not call System.exit(n) at end of compilation (n==0 if
no error)
    -repeat <n>        repeat compilation process <n> times for perf analysis
    @<file>            read command line arguments from file

    -? -help           print this help message
    -v -version        print compiler version
    -showversion       print compiler version and continue

{0}

        Usage: <options> <source file | @argfile>..

AspectJ-specific options:
        -inpath <list>      use classes in dirs and jars/zips in <list> as sourc
e
                            (<list> uses platform-specific path delimiter)
        -injars <jarList>   use classes in <jarList> zip files as source
                            (<jarList> uses classpath delimiter)
                            deprecated - use inpath instead.
        -aspectpath <list>  weave aspects in .class files from <list> dirs and j
ars/zip into sources
                            (<list> uses classpath delimiter)
        -outjar <file>      put output classes in zip file <file>
        -outxml             generate META-INF/aop.xml
        -outxmlfile <file>  specify alternate destination output of -outxml
        -argfile <file>     specify line-delimited list of source files
        -showWeaveInfo      display information about weaving
        -incremental        continuously-running compiler, needs -sourceroots
                            (reads stdin: enter to recompile and 'q' to quit)
        -sourceroots <dirs> compile all .aj and .java files in <dirs>
                            (<dirs> uses classpath delimiter)
        -crossrefs          generate .ajsym file into the output directory
        -emacssym           generate .ajesym symbol files for emacs support
        -Xlint              same as '-Xlint:warning'
        -Xlint:<level>      set default level for crosscutting messages
                            (<level> may be ignore, warning, or error)
        -Xlintfile <file>   specify properties file to set per-message levels
                            (cf org/aspectj/weaver/XlintDefault.properties)
        -X                  print help on non-standard options

Standard Eclipse compiler options:
Options enabled by default are prefixed with '+'

Classpath options:
    -cp -classpath <directories and zip/jar files separated by ;>
                       specify location for application classes and sources
    -bootclasspath <directories and zip/jar files separated by ;>
                       specify location for system classes
    -d <dir>           destination directory (if omitted, no directory is create
d)
    -d none            generate no .class files
    -encoding <enc>    specify custom encoding for all sources. Each file/direct
ory can override it
                       when suffixed with '['<enc>']' (e.g. X.java[utf8])

Compliance options:
    -1.3               use 1.3 compliance level (implicit -source 1.3 -target 1.
1)
    -1.4             + use 1.4 compliance level
    -1.5               use 1.5 compliance level
    -1.6               use 1.6 compliance level
    -source <version>  set source level (1.3, 1.4, 1.5 or 1.6)
    -target <version>  set classfile target (1.1 to 1.4)

Warning options:
    -deprecation     + deprecation outside deprecated code
    -nowarn            disable all warnings except xlint or declare warning
    -warn:none         disable all warnings except xlint or declare warning
    -warn:<warnings separated by ,>    enable exactly the listed warnings
    -warn:+<warnings separated by ,>   enable additional warnings
    -warn:-<warnings separated by ,>   disable specific warnings
      allDeprecation       deprecation including inside deprecated code
      allJavadoc           invalid or missing javadoc
      assertIdentifier   + 'assert' used as identifier
      charConcat         + char[] in String concat
      conditionAssign      possible accidental boolean assignment
      constructorName    + method with constructor name
      deprecation        + deprecation outside deprecated code
      emptyBlock           undocumented empty block
      fieldHiding          field hiding another variable
      finally            + finally block not completing normally
      indirectStatic       indirect reference to static member
      intfNonInherited   + interface non-inherited method compatibility
      javadoc              invalid javadoc
      localHiding          local variable hiding another variable
      maskedCatchBlock   + hidden catch block
      nls                  string literal lacking non-nls tag //$NON-NLS-<n>$
      noEffectAssign     + assignment without effect
      pkgDefaultMethod   + attempt to override package-default method
      semicolon            superfluous semicolon
      unqualifiedField     unqualified reference to field
      unusedImport       + unused import declaration
      unusedLocal          unread local variable
      unusedPrivate        unused private member declaration
      unusedThrown         unused declared thrown exception
      uselessTypeCheck     unnecessary cast/instanceof operation
      specialParamHiding   constructor or setter parameter hiding another field
      staticReceiver     + non-static reference to static member
      syntheticAccess      synthetic access for innerclass
      tasks(<tags separated by |>) tasks identified by tags inside comments

Debug options:
    -g[:lines,vars,source] custom debug info
    -g:lines,source  + both lines table and source debug info
    -g                 all debug info
    -g:none            no debug info
    -preserveAllLocals preserve unused local vars for debug purpose

Advanced options:
    -log <file>        log to a file
    -proceedOnError    do not stop at first error, dumping class files with prob
lem methods
    -verbose           enable verbose output
    -referenceInfo     compute reference info
    -progress          show progress (only in -log mode)
    -time              display speed information
    -noExit            do not call System.exit(n) at end of compilation (n==0 if
no error)
    -repeat <n>        repeat compilation process <n> times for perf analysis
    @<file>            read command line arguments from file

    -? -help           print this help message
    -v -version        print compiler version
    -showversion       print compiler version and continue

下面是最简单一个helloworld程序。

1. 最简单的hello程序。
public class Hello {

     public void sayHello(){
       System.out.println("Hello AspectJ.");
    }

    public static void main(String[] args) {
       Hello hello = new Hello();
       hello.sayHello();
    }
}

编译运行结果：
D:\java\aspectjDemo>javac Hello.java

D:\java\aspectjDemo>java Hello
Hello AspectJ.


2. 不改变Hello.java文件，在调用sayHello前后打log。

public aspect TestAspect{

    void around():call(void Hello.sayHello()){
       System.out.println("begin transaction....");
       proceed();//代表调用原来的sayHello()方法
        System.out.println("end transaction....");
    }
}

编译运行结果：
D:\java\aspectjDemo>dir *
驱动器 D 中的卷是 SOFTWARE
卷的序列号是 8236-DBD6

D:\java\aspectjDemo 的目录

2011/10/11  22:55    <DIR>          .
2011/10/11  22:55    <DIR>          ..
2011/10/11  22:56               249 Hello.java
2011/10/11  22:57               252 TestAspect.java
               2 个文件            501 字节
               2 个目录 80,415,948,800 可用字节

D:\java\aspectjDemo> ajc *.java

D:\java\aspectjDemo>java Hello
begin transaction....
Hello AspectJ.
end transaction....

D:\java\aspectjDemo>