javac命令说明

root@k8smaster01 json]# javac
Usage: javac <options> <source files>
where possible options include:
  -g                         Generate all debugging info 
  -g:none                    Generate no debugging info 
  -g:{lines,vars,source}     Generate only some debugging info
  -nowarn                    Generate no warnings
  -verbose                   Output messages about what the compiler is doing
  -deprecation               Output source locations where deprecated APIs are used
  -classpath <path>          Specify where to find user class files and annotation processors
  -cp <path>                 Specify where to find user class files and annotation processors #指定编译java源文件需要依赖的.class文件的路径，可以是目录，jar文件，zip文件（里面都是class文件）
  -sourcepath <path>         Specify where to find input source files #指定编译java源文件需要依赖的java文件的路径，可以是目录，jar文件，zip文件（里面都是java文件）
  -bootclasspath <path>      Override location of bootstrap class files
  -extdirs <dirs>            Override location of installed extensions
  -endorseddirs <dirs>       Override location of endorsed standards path
  -proc:{none,only}          Control whether annotation processing and/or compilation is done.
  -processor <class1>[,<class2>,<class3>...] Names of the annotation processors to run; bypasses default discovery process
  -processorpath <path>      Specify where to find annotation processors
  -parameters                Generate metadata for reflection on method parameters
  -d <directory>             Specify where to place generated class files #指定生成的class的位置，会根据包名递归生成
  -s <directory>             Specify where to place generated source files
  -h <directory>             Specify where to place generated native header files
  -implicit:{none,class}     Specify whether or not to generate class files for implicitly referenced files
  -encoding <encoding>       Specify character encoding used by source files #指定源文件使用的字符编码
  -source <release>          Provide source compatibility with specified release
  -target <release>          Generate class files for specific VM version #为特定虚拟机版本生成类文件
  -profile <profile>         Check that API used is available in the specified profile
  -version                   Version information
  -help                      Print a synopsis of standard options
  -Akey[=value]              Options to pass to annotation processors
  -X                         Print a synopsis of nonstandard options
  -J<flag>                   Pass <flag> directly to the runtime system
  -Werror                    Terminate compilation if warnings occur
  @<filename>                Read options and filenames from file @一个或多个对源文件进行列表的文件
[root@k8smaster01 json]# 

案例

1）简单单个无package的java文件编译
[root@k8smaster01 daima]# mkdir simpledemo #创建目录
[root@k8smaster01 daima]# cd simpledemo/
[root@k8smaster01 simpledemo]# pwd
/data/java/daima/simpledemo
[root@k8smaster01 simpledemo]# vi Test.java  #编辑Test.java文件，打印一行文字
[root@k8smaster01 simpledemo]# more Test.java 
public class Test {

  public static void main(String[] args) {
     System.out.println("javac simple demo");
  }
}
[root@k8smaster01 simpledemo]# javac Test.java -d .  #使用javac编译，class存放在当前目录
[root@k8smaster01 simpledemo]# ls -lrt
total 8
-rw-r--r-- 1 root root 116 Mar  3 23:39 Test.java
-rw-r--r-- 1 root root 419 Mar  3 23:40 Test.class
[root@k8smaster01 simpledemo]# java Test  #执行class文件，正常打印javac simple demo数据
javac simple demo
[root@k8smaster01 simpledemo]#

2）简单单个有package的java文件编译
[root@k8smaster01 simpledemo]# mkdir -p src/com/test #新建目录
[root@k8smaster01 simpledemo]# mv Test.java src/com/test/ #拷贝之前的Test的java文件
[root@k8smaster01 simpledemo]# vi src/com/test/Test.java  #编辑java文件，新增package
[root@k8smaster01 simpledemo]# more src/com/test/Test.java 
package com.test;
public class Test {

  public static void main(String[] args) {
     System.out.println("javac simple demo");
  }
}
[root@k8smaster01 simpledemo]# tree /data/java/daima/simpledemo/  #目录结构
/data/java/daima/simpledemo/
└── src
    └── com
        └── test
            └── Test.java

3 directories, 1 file
[root@k8smaster01 simpledemo]# mkdir clazz #新增clazz目录存放编译后的class文件
[root@k8smaster01 simpledemo]# ls -lrt
total 0
drwxr-xr-x 3 root root 16 Mar  3 23:43 src
drwxr-xr-x 2 root root  6 Mar  3 23:46 clazz
[root@k8smaster01 simpledemo]# javac src/com/test/Test.java -d ./clazz/  #使用javac编译
[root@k8smaster01 simpledemo]# tree /data/java/daima/simpledemo/  #编译后的目录结构
/data/java/daima/simpledemo/
├── clazz
│   └── com
│       └── test
│           └── Test.class
└── src
    └── com
        └── test
            └── Test.java

6 directories, 2 files
[root@k8smaster01 simpledemo]# java -cp clazz/ com.test.Test  #运行编译后的文件，正常打印javac simple demo
javac simple demo
[root@k8smaster01 simpledemo]# 

3）批量的的java文件编译(涉及有依赖包)
[root@k8smaster01 Test]# tree /data/java/daima/Test  #工程代码结构
/data/java/daima/Test
├── clazz
├── config
├── lib
│   └── gson-2.3.jar
└── src
    └── com
        ├── data
        │   └── ParaMap.java
        └── json
            └── Test.java

7 directories, 3 files
[root@k8smaster01 daima]# more src/com/data/ParaMap.java 
package com.data;

import java.util.HashMap;
import java.util.Map;

public class ParaMap {
  public static Map<String,String> getMap(){
      Map<String,String> sysParams = new HashMap<String,String>();
      sysParams.put("localForceNewThread", "true");
      sysParams.put("uuid", "28bcf60840f8416e8ea55ffe970c1623");
      sysParams.put("log", "348a8a27e315e5a26c68a002.348a8a27e315e5a26c68a003.0");
      return sysParams;
  }
}

[root@k8smaster01 daima]# more src/com/json/Test.java 
package com.json;

import java.util.Map;
import com.data.ParaMap;
import com.google.gson.Gson;

public class Test {
    public static void main(String[] args) {
        Gson gson = new Gson();
        Map<String, String> sysParams = ParaMap.getMap();
        String json=gson.toJson(sysParams);
        System.out.println(json);
    }

}

[root@k8smaster01 daima]#
[root@k8smaster01 daima]# more javac.sh  #编译脚本，编译后的文件放在clazz中
#!/bin/bash

PROCESS_NAME=test_javac
BASE_APP_HOME="/data/java/daima/Test"
jars=`ls ${BASE_APP_HOME}/lib`
for jar in $jars
do
        CLASSPATH=${BASE_APP_HOME}/lib/$jar:$CLASSPATH
done

CLASSPATH="${BASE_APP_HOME}/config:${CLASSPATH}"
export CLASSPATH

echo "CLASSPATH=${CLASSPATH}"
find ${BASE_APP_HOME} -name "*.java" > ${BASE_APP_HOME}/sources.txt
sourcesclazz=`cat ${BASE_APP_HOME}/sources.txt`
echo "${sourcesclazz}"
javac -encoding UTF-8    -cp ${CLASSPATH} -d ${BASE_APP_HOME}/clazz  @${BASE_APP_HOME}/sources.txt
[root@k8smaster01 daima]# sh javac.sh  #执行编译
CLASSPATH=/data/java/daima/Test/config:/data/java/daima/Test/lib/gson-2.3.jar:.:/data/java/jdk18/lib/dt.jar:/data/java/jdk18/lib/tools.jar
/data/java/daima/Test/src/com/json/Test.java
/data/java/daima/Test/src/com/data/ParaMap.java
[root@k8smaster01 daima]# cp -r Test/clazz/com/ Test/config/ #拷贝编译后的文件到config目录
[root@k8smaster01 daima]# ls -lrt Test/config/
total 0
drwxr-xr-x 4 root root 28 Mar  4 00:08 com
[root@k8smaster01 daima]# 

[root@k8smaster01 daima]# more java.sh  #运行编译后的文件
#!/bin/bash

PROCESS_NAME=test_java
BASE_APP_HOME="/data/java/daima/Test"
jars=`ls ${BASE_APP_HOME}/lib`
for jar in $jars
do
        CLASSPATH=${BASE_APP_HOME}/lib/$jar:$CLASSPATH
done
CLASSPATH="${BASE_APP_HOME}/config:${CLASSPATH}"
export CLASSPATH
echo "CLASSPATH=${CLASSPATH}"
java -cp ${CLASSPATH} com.json.Test
[root@k8smaster01 daima]# sh java.sh  #运行编译后的文件，正常打印json串
CLASSPATH=/data/java/daima/Test/config:/data/java/daima/Test/lib/gson-2.3.jar:.:/data/java/jdk18/lib/dt.jar:/data/java/jdk18/lib/tools.jar
{"log":"348a8a27e315e5a26c68a002.348a8a27e315e5a26c68a003.0","localForceNewThread":"true","uuid":"28bcf60840f8416e8ea55ffe970c1623"}
[root@k8smaster01 daima]#

 

链接：https://pan.baidu.com/s/1ZLHiJ9fapVzjYV7BkIisrg  相关代码