Javac Java Command-line compilation Run program

Reference from: http://blog.csdn.net/xxyyww/article/details/5784803

Objective:

When running Java at the command line, the thing to do is not to click on the mouse. If a third-party jar package is used again, the command is longer. A good way to do this is to use ant, but I found a problem when using ant in the command line, its input is just as painful as the Eclipse console. Like what:

Scanner in = new Scanner (system.in);

System.out.println ("Please enter an integer:");

int a = In.nextint ();

The results of these three lines of code:

23

Please enter an integer

This show is not what I want, so I use makefile here. Another reason is I'm not very good at ant.

PS: Not discussed here such as not packing or. class files in the same directory as the. java files

Without a third-party packageMy file layout

[Email protected]:~/code/gongda/data_java/test3$ tree.├──classes├──makefile└──src    └──com        └──laolang            ├──domain            │└──person.java            └──main                └──main.java6 directories, 3 Files[email Protected]:~/code/gongda/da ta_java/test3$

Person.java

[email protected]:~/code/gongda/data_java/test3$ Cat Src/com/laolang/domain/person.java 1package     Com.laolang.domain;     2 3public class Person {4 5public person () {6super (); 7//TODO auto-generated constructor stub 8} 9 10public Person (string name, string birthday, String desc) {1    1super ();    12this.name = name;    13this.birthday = Birthday;    14THIS.DESC = desc;    17@override 18public String toString () {19return "person [name=" + name + ", birthday=" + Birthday    20+ ", desc=" + desc + "]";    23public String GetName () {24return name;    27public void SetName (String name) {28this.name = name;    31public String Getbirthday () {32return birthday;    35public void Setbirthday (String birthday) {36this.birthday = birthday;    PNS 39public String GetDesc () {40return desc; 43public void Setdesc (String desc) {44this.desc = Desc    47private String name;    48private String birthday;    49private String desc; 50}[email protected]:~/code/gongda/data_java/test3$

Main.java

[Email protected]:~/code/gongda/data_java/test3$ cat Src/com/laolang/main/main.java      1package com.laolang.main;     2     3     4import Com.laolang.domain.Person;     5     6public class Main {     7     8public static void Main (string[] args) {     9    10Person person = new Person ("small Code "," 91-12-06 "," programmer ");    11SYSTEM.OUT.PRINTLN (person);    14}[email protected]:~/code/gongda/data_java/test3$

My makefile.

1     javac command     3javac=javac     4# java command     5java=java     6     7#. class file directory     8classes_dir=classes     9    10# Java source file path    11java_src=src    13# start class name    14mainclass=com.laolang.main.main    16# Startup class file path    17mainfile=src/com/laolang/main/main.java    20comp:    21 $ (JAVAC)-sourcepath $ (JAVA_SRC)  $ (mainfile)-D $ (classes_dir    )    23run:    24$ (JAVA)-classpath $ ( Classes_dir) $ (MAINCLASS)    26clean:    27cd classes;rm-rfv com    28[email protected]:~/code/ gongda/data_java/test3$

Operating effect:

[Email protected]:~/code/gongda/data_java/test3$ Tree.├──classes├──makefile└──src└──com└──laolang ├──DOMAIN│  └──PERSON.JAVA└──MAIN└──MAIN.JAVA6 Directories , 3 files[email protected]:~/code/gongda/data_java/test3$ makejavac-sourcepath src src/com/laolang/main/ Main.java-d classes[email protected]:~/code/gongda/data_java/test3$ tree.├──classes│  └──com│   └──laolang│  ├──domain│  │  └──person.class│ &nb         Sp            └──main│  └──main.class├──makefile└──src└──com└──laolang├──domain │  └──PERSON.JAVA└──MAIN└──MAIN.JAVA10 directories, 5 files[email  protected]:~/code/gongda/data_java/test3$ make Runjava-classpath classes Com.laolang.main.MainPerson [name= Small Code, birthday=91-12-06, desc= programmer][EMAIL PRotected]:~/code/gongda/data_java/test3$ make cleancd classes;rm-rfv com deleted "Com/laolang/main/main.class" deleted directory: "com/ Laolang/main "deleted" Com/laolang/domain/person.class "deleted directory:" Com/laolang/domain "deleted directory:" Com/laolang "deleted directory:" com "[            email protected]:~/code/gongda/data_java/test3$ Tree.├──classes├──makefile└──src└──com└──laolang  ├──DOMAIN│  └──PERSON.JAVA└──MAIN└──MAIN.JAVA6 directories, 3 files[email protected]:~/code/gongda/data_java/test3$

Command analysis:

{In fact, no analysis, just a note}

The commands which are compiled are:

Javac-sourcepath src  src/com/laolang/main/main.java-d classes

Javac

I don't have to say that.

-sourcepath SRC

Instructions from Javac:-sourcepath < paths > specifying where to find input source files

That is, the location of the specified source file

Src/com/laolang/main/main.java

Start the source file for the class

-D Classes

Instructions from Javac:-D < directory > specify where to place the generated class file

This is where the specified generated. class file is placed

command to run:

Java-classpath Classes Com.laolang.main.Main

Java

That's not to mention.

-classpath classes

-classpath and-CP, the difference is that a full name is a short, specify the directory where the. class file resides

Com.laolang.main.Main

The. class file for the startup classes

Canonical command and Code layout

This is to say, for example, my source files are placed under SRC

The packing code for Main.java and Person.java is

Main.java:package Com.laolang.main;

Person.java:package Com.laolang.domain;

Then my Main.java's path should be Src/com/laolang/main/main.java.

The path to the Person.java should be Src/com/laolang/domain/person.java

Then I should create a directory classes or something, to store the. class file, so that using the-D classes option, you can separate the. java file from the. class file with the Javac command.

With third-party jar packagesCode layout:

[Email protected]:~/code/gongda/data_java/test2$ Tree.├──classes├──data│└──person.xml├──lib│└──dom4j.jar├──mak EFILE└──SRC    └──com        └──laolang            ├──domain            │└──person.java            ├──handle            │└──xmlhandle.java< C6/>└──main                

Xmlhandle.java

[email protected]:~/code/gongda/data_java/test2$ Cat Src/com/laolang/handle/xmlhandle.java 1package     Com.laolang.handle;     2 3import Java.io.File;     4import Java.util.Iterator;     5 6import org.dom4j.Document;     7import org.dom4j.DocumentException;     8import org.dom4j.Element;    9import Org.dom4j.io.SAXReader; 11public class Xmlhandle {13public static void main (string[] args) {14try {15XmlHandle handle = NE    W xmlhandle ("Data/person.xml");    16handle.show ();    The catch (Documentexception e) {18e.printstacktrace ();    22public Xmlhandle () {23super ();    26public Xmlhandle (String fileName) throws documentexception {27this.filename = FileName;    28SAXReader sax = new Saxreader ();    29this.document = Sax.read (new File);    32@override 33public String toString () {34return "Xmlhanle [filename=" + FileName + "]"; 37public void Show () {38ElemeNT root = This.document.getRootElement ();    39list (root);    42private void list (element element) {43system.out.println (Element.getname ());    45Iterator it = Element.elementiterator ();    47while (It.hasnext ()) {48Element E = (Element) it.next ();    49list (e);    (): 54public String GetFileName () {55return fileName;    58public void Setfilename (String fileName) {59this.filename = FileName;    62private String FileName;    64private document document;  66}[email protected]:~/code/gongda/data_java/test2$

Main.java

[Email protected]:~/code/gongda/data_java/test2$ cat Src/com/laolang/main/main.java      1package com.laolang.main;     2     3import org.dom4j.DocumentException;     4     5import Com.laolang.domain.Person;     6import Com.laolang.handle.XmlHandle;     7     8public class Main {     9    10public static void Main (string[] args) {    one    12Person person = new Person ( "Small Code", "91-12-06", "programmer");    13SYSTEM.OUT.PRINTLN (person);    15try {    16XmlHandle handle = new Xmlhandle ("Data/person.xml");    17handle.show ();    * catch (Documentexception e) {    19e.printstacktrace ();    21}    

Person.xml

[Email protected]:~/code/gongda/data_java/test2$ cat data/person.xml      1<?xml version= "1.0" encoding= "UTF-8"? >     2<perlist>     3<person>     4<name> Small code </name>     5<birthday>91-12-06 </birthday>     6<desc> A god-like man </desc>     7</person>     8     9<person>    10 <name> Tianya </name>    11<birthday>91-11-01</birthday>    12<desc> Rangers </desc >    13</person>    15<person>    16<name> old Wolf </name>    17< Birthday>71-12-06</birthday>    18<desc> killer </desc>    19</person>    21<person>    22<name> Walker </name>    23<birthday>81-12-06</birthday>    24 <desc> Monk </desc>    25</person>    

My present makefile.

[Email protected]:~/code/gongda/data_java/test2$ cat Makefile      1 *     javac command     3javac=javac     4# java command     5java=java     6     7#. class file directory     8classes_dir=classes     9    10# The path where the Java source files are located    11java_src=src    13# Startup class name    14mainclass=com.laolang.main.main 16# the    path where the startup class is located    17mainfile=src/com/ Laolang/main/main.java    19# dom4j path    20dom4j=lib/dom4j.jar    22comp:    23$ ( JAVAC)-sourcepath $ (JAVA_SRC)-classpath $ (Classes_dir): $ (dom4j) $ (mainfile)-D $ (classes_dir    )    25run:    26$ (JAVA)-classpath $ (Classes_dir): $ (dom4j) $ (MAINCLASS)    28clean:    29cd classes;rm-rfv com    

Operating effect:

[Email protected]:~/code/gongda/data_java/test2$ tree.├──classes├──data│  └──person.xml├──lib│    └──dom4j.jar├──Makefile└──src└──com└──laolang├──domain│   └──person.java├──handle│  └──xmlhandle.java└──main└── MAIN.JAVA9 directories, 6 files[email protected]:~/code/gongda/data_java/test2$ makejavac-sourcepath src- Classpath Classes:lib/dom4j.jar src/com/laolang/main/main.java-d Classes[email protected]:~/code/gongda/data _java/test2$ Tree.├──classes│  └──com│  └──laolang│  ├──domain│ &nbs         P │  └──person.class│  ├──handle│  │  └──xmlhandle.class│&nbs p; └──main│  └──main.class├──data│  └──person.xml├──lib│   └──dom4j.jar├──makefile└──src└── com└──laolang├──domain│  └──person.java├──handle│& NBSP; └──XMLHANDLE.JAVA└──MAIN└──MAIN.JAVA14 directories, 9 files[email protecte d]:~/code/gongda/data_java/test2$ make Runjava-classpath classes:lib/dom4j.jar Com.laolang.main.MainPerson [name= Small code, BIRTHDAY=91-12-06, desc= programmer] perlistpersonnamebirthdaydescpersonnamebirthdaydescpersonnamebirthdaydescpersonnamebirthdaydesc[email  protected]:~/code/gongda/data_java/test2$ make cleancd classes;rm-rfv com deleted "Com/laolang/main/main.class" Deleted directory: " Com/laolang/main "deleted" Com/laolang/domain/person.class "deleted directory:" Com/laolang/domain "deleted" com/laolang/handle/ Xmlhandle.class "deleted directory:" Com/laolang/handle "deleted directory:" Com/laolang "deleted directory:" com "[email protected]:~/code/gongda/ data_java/test2$ tree.├──classes├──data│  └──person.xml├──lib│  └──dom4j.jar├──makefile└──    Src└──com└──laolang├──domain        │  └──person.java├──handle│  └──xmlhandle.java└──mai  N└──MAIN.JAVA9 directories, 6 files[email protected]:~/code/gongda/data_java/test2$

Command analysis:

Compile command

Javac-sourcepath Src-classpath Classes:lib/dom4j.jar src/com/laolang/main/main.java-d Classes

Here's the point:-classpath Classes:lib/dom4j.jar

For the time being not understand what this writing principle is, basically is what jar package, just add after classes, multiple jar package to; Separated

I tried one, without a third-party jar package, the compile command plus-classpath classes is also possible.

command to run:

Java-classpath Classes:lib/dom4j.jar Com.laolang.main.Main

It's the same here as above.

Javac Java Command-line compilation Run program