javac 编译java源文件时，提示 package does not exist 的错误
Test.java
import java.security.MessageDigest;
import org.apache.commons.codec.binary.Hex;
public class Test{
public static void main(String args[]){
boolean isAlarmed = true;
boolean aa = isAlarmed || false;
String queryTimestamp = "1970-01-01T00:00:00+0000";
System.out.println(queryTimestamp.getBytes());
try{
MessageDigest md5 = MessageDigest.getInstance("MD5");
System.out.println(md5.digest("stringtodigest".getBytes()));
byte[] value = "stringtodigest".getBytes();
md5.update(value);
byte[] digest = md5.digest();
System.out.println(new String(Hex.encodeHex(digest)));
System.out.println(md5.digest("stringtodigest".getBytes()));
System.out.println(md5.digest("stringtodigest".getBytes()));
}catch(Exception e){
}
}
}
javac Test.java编译的时候报错！
解决办法：
1. 到mvn repository(http://mvnrepository.com/artifact/commons-codec/commons-codec/1.7)上面吧缺少的 jar 包下载下来，
2. 然后给 CLASSPATH 环境变量在添加一下这个jar 包所在的路径，就可以了。
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参考：https://www.linuxquestions.org/questions/programming-9/javac-compiling-error-mising-package-669775/
javac compiling error ( mising package)
First i have to say I am very new to java. I downloaded java codes from the Internet and try to compile them using javac. I got following error,
Code:
C: empjavacrypt>"C:Program FilesJavajdk1.6.0_06injavac" RSAExample.java
.BaseCrypto.java:1: package org.apache.commons.codec does not exist
import org.apache.commons.codec.DecoderException;
^
.BaseCrypto.java:2: package org.apache.commons.codec.binary does not exist
import org.apache.commons.codec.binary.Hex;
^
.BaseCrypto.java:26: cannot find symbol
symbol : class DecoderException
location: class BaseCrypto
public static byte[] asByte(String hexString) throws DecoderException {
^
.BaseCrypto.java:16: cannot find symbol
symbol : variable Hex
location: class BaseCrypto
return new String(Hex.encodeHex(buf));
^
.BaseCrypto.java:27: cannot find symbol
symbol : variable Hex
location: class BaseCrypto
return Hex.decodeHex(hexString.toCharArray());
^
5 errors
I guess i just missed some packages like "org.apache.commons.codec.*",
and that package is not part of standard jdk, right?
How do i get those package? I also have netbean and eclipse, but I haven't tried to use them yet.
-----------------
When you get the package, which is probably a .jar file, add that .jar file to your classpath (environment variable).
EDIT: Specifically, here.
EDIT: I believe on Windows it's something like...
SET CLASSPATH=%CLASSPATH%;C:path ojarjarfile.jar
----------------------
I downloaded the jar file suggested by elprawn, and it work great!! thank you so much.
I am curious about the suggestion from jay73. Is the package management the software like "yum" or "apt-get", right? What keyword should use to search for it?
----------------------
On a system that uses apt, you can use
aptitude search commons
and you'should get a list of the available commons libraries.On ubuntu:
jurgen@Selena:~$ aptitude search commons i libcommons-attributes-java - adds C#/.Net-style attributes to Java code i A libcommons-beanutils-java - utility for manipulating JavaBeans i libcommons-beanutils-java-doc - Javadoc API for libcommons-beanutils-java i A libcommons-cli-java - API for working with the command line argu i A libcommons-codec-java - encoder and decoders such as Base64 and he i A libcommons-collections-java - A set of abstract data type interfaces and i A libcommons-collections3-java - A set of abstract data type interfaces and i libcommons-collections3-java-do - Documentation for libcommons-collections3- i libcommons-configuration-java - Java based library providing a generic con p libcommons-csv-java - a Java library for working with csv (comma p libcommons-csv-java-doc - documentation for libcommons-csv-java i A libcommons-daemon-java - library to launch Java applications as dae i A libcommons-dbcp-java - Database Connection Pooling Services i A libcommons-digester-java - Rule based XML Java object mapping tool p libcommons-discovery-java - locates classes that implement a given Jav i A libcommons-el-java - Implementation of the JSP2.0 Expression La i libcommons-fileupload-java - File upload capability to your servlets an i libcommons-httpclient-java - A Java(TM) library for creating HTTP clien i libcommons-httpclient-java-doc - Documentation for libcommons-httpclient-ja i libcommons-io-java - Common useful IO related classes i libcommons-io-java-doc - Common useful IO related classes - documen p libcommons-jexl-java - expression language engine p libcommons-jxpath-java - manipulate javabean using XPath syntax p libcommons-jxpath-java-doc - Javadoc API for libcommons-jxpath-java i A libcommons-lang-java - Extension of the java.lang package i A libcommons-launcher-java - cross platform java application launcher i A libcommons-logging-java - commmon wrapper interface for several logg i A libcommons-modeler-java - convenience library to use Java Management i libcommons-modeler-java-doc - documentation and examples for Commons Mod i libcommons-net-java - internet protocol suite Java library p libcommons-openpgp-java - a common and simple interface for generati p libcommons-openpgp-java-doc - a common and simple interface for generati i A libcommons-pool-java - pooling implementation for Java objects i libcommons-validator-java - ease and speed development and maintenance p libgettext-commons-java - Java classes for internationalization (i18 p libhibernate-commons-annotation - Hibernate Commons Annotations p libws-commons-util-java - Common utilities from the Apache Web Servi p libxml-commons-resolver1.1-java - XML entity and URI resolver library p libxml-commons-resolver1.1-java - XML entity and URI resolver library -- doc p libxml-commons-resolver1.1-java - XML entity and URI resolver library -- nat i libxmlgraphics-commons-java - reusable components used by Batik and FOP