发布于

Mysql自定义函数报错解决方法

在MySql中创建自定义函数报错信息如下：

ERROR 1418 (HY000): This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)

解决方法：

mysql>set global log_bin_trust_function_creators=1;

发布于

mysqld: Can’t read dir of ‘/etc/mysql/conf.d/’ (Errcode: 13 – Permission denied)

在安装docker mysql：8.0版本时，出现错误：

mysqld: Can’t read dir of ‘/etc/mysql/conf.d/’ (Errcode: 13 – Permission denied)
mysqld: [ERROR] Fatal error in defaults handling. Program aborted!

ERROR: mysqld failed while attempting to check config
command was: “mysqld –verbose –help”

原因

因为Centos7安全Selinux禁止了一些安全权限，导致mysql和mariadb在进行挂载/var/lib/mysql的时候会提示如下信息

解决方法

在docker run中加入 –privileged=true 给容器加上特定权限

附上 MySQL 创建命令:

docker run –privileged=true –restart=always -itd –name mysql8 -p 3306:3306 -e MYSQL_ROOT_PASSWORD=’123456′  -v /www/mysql/conf:/etc/mysql/conf.d -v /www/mysql/mysqldata:/var/lib/mysql  mysql –character-set-server=utf8mb4 –collation-server=utf8mb4_unicode_ci

发布于

Centos 7 execute yum update ——File “/usr/libexec/urlgrabber-ext-down”, line 75, in

问题：

Traceback (most recent call last):
  File "/usr/libexec/urlgrabber-ext-down", line 75, in <module>
    main()
  File "/usr/libexec/urlgrabber-ext-down", line 61, in main
    fo = PyCurlFileObject(opts.url, opts.filename, opts)
  File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1258, in __init__
    self._do_open()
  File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1589, in _do_open
    self._do_grab()
  File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1723, in _do_grab
    self._do_perform()
  File "/usr/lib/python2.7/site-packages/urlgrabber/grabber.py", line 1517, in _do_perform
    raise KeyboardInterrupt
KeyboardInterrupt

解决方案：

    打开这个文件：/usr/lib/python2.7/site-packages/urlgrabber/grabber.py

找到 elif errcode in (42, 55, 56):   

    用  elif errcode == 42:替换

发布于

maven打包依赖到lib目录

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <executions>
                <execution>
                    <id>copy-dependencies</id>
                    <phase>package</phase>
                    <goals>
                        <goal>copy-dependencies</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>target/lib</outputDirectory>
                        <excludeTransitive>false</excludeTransitive>
                        <stripVersion>true</stripVersion>
                    </configuration>
                </execution>
            </executions>
        </plugin>
        <!--java代码打包插件，不会将依赖也打包-->
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
        </plugin>
    </plugins>
</build>
发布于

在类路径或引导类路径中找不到程序包 java.lang

这是在基于 maven 编写java项目的时候，使用 mvn install 时发生的异常，异常信息如下

[源文件的搜索路径: /Users/Frank/workspace-java/project/app-web/src/main/java,/Users/Frank/workspace-java/project/app-web/target/generated-sources/annotations]  [类文件的搜索路径: /Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/rt.jar;/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/jce.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/cldrdata.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/dnsns.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/jaccess.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/jfxrt.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/localedata.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/nashorn.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/sunec.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/lib/ext/zipfs.jar,/System/Library/Java/Extensions/MRJToolkit.jar,/Users/Frank/workspace-java/projects/app-web/target/classes,/Users/Frank/workspace-java/hnProjects/app-configs/target/app-configs-1.0-SNAPSHOT.jar,/Users/Frank/workspace-java/hnProjects/app-utils/target/app-utils-1.0-SNAPSHOT.jar,/Users/Frank/.m2/repository/org/apache/commons/commons-lang3/3.3.2/commons-lang3-3.3.2.jar,/Users/Frank/.m2/repository/commons-httpclient/commons-httpclient/3.1/commons-httpclient-3.1.jar,/Users/Frank/.m2/repository/commons-codec/commons-codec/1.9/commons-codec-1.9.jar,/Users/Frank/.m2/repository/commons-collections/commons-collections/3.2.1/commons-collections-3.2.1.jar,/Users/Frank/.m2/repository/org/apache/httpcomponents/httpclient/4.3.6/httpclient-4.3.6.jar,/Users/Frank/.m2/repository/org/apache/httpcomponents/httpcore/4.3.3/httpcore-4.3.3.jar,/Users/Frank/.m2/repository/commons-logging/commons-logging/1.1.3/commons-logging-1.1.3.jar,/Users/Frank/.m2/repository/commons-beanutils/commons-beanutils/1.9.2/commons-beanutils-1.9.2.jar,/Users/Frank/.m2/repository/org/apache/ant/ant/1.9.4/ant-1.9.4.jar,/Users/Frank/.m2/repository/org/apache/ant/ant-launcher/1.9.4/ant-launcher-1.9.4.jar,/Users/Frank/.m2/repository/net/sf/json-lib/json-lib/2.4/json-lib-2.4-jdk15.jar,/Users/Frank/.m2/repository/commons-lang/commons-lang/2.5/commons-lang-2.5.jar,/Users/Frank/.m2/repository/net/sf/ezmorph/ezmorph/1.0.6/ezmorph-1.0.6.jar,/Users/Frank/.m2/repository/com/github/junrar/junrar/0.7/junrar-0.7.jar,/Users/Frank/.m2/repository/com/github/junrar/junrar/0.7/commons-logging-api-1.1.jar,/Users/Frank/.m2/repository/com/github/junrar/junrar/0.7/commons-vfs2-2.0.jar,/Users/Frank/.m2/repository/com/github/junrar/junrar/0.7/commons-logging-1.1.1.jar,/Users/Frank/.m2/repository/com/github/junrar/junrar/0.7/maven-scm-api-1.4.jar,/Users/Frank/.m2/repository/com/github/junrar/junrar/0.7/plexus-utils-1.5.6.jar,/Users/Frank/.m2/repository/com/github/junrar/junrar/0.7/maven-scm-provider-svnexe-1.4.jar,/Users/Frank/.m2/repository/com/github/junrar/junrar/0.7/maven-scm-provider-svn-commons-1.4.jar,/Users/Frank/.m2/repository/com/github/junrar/junrar/0.7/regexp-1.3.jar,/Users/Frank/.m2/repository/commons-logging/commons-logging-api/1.1/commons-logging-api-1.1.jar,/Users/Frank/.m2/repository/org/apache/commons/commons-vfs2/2.0/commons-vfs2-2.0.jar,/Users/Frank/.m2/repository/org/apache/maven/scm/maven-scm-api/1.4/maven-scm-api-1.4.jar,/Users/Frank/.m2/repository/org/codehaus/plexus/plexus-utils/1.5.6/plexus-utils-1.5.6.jar,/Users/Frank/.m2/repository/org/apache/maven/scm/maven-scm-provider-svnexe/1.4/maven-scm-provider-svnexe-1.4.jar,/Users/Frank/.m2/repository/org/apache/maven/scm/maven-scm-provider-svn-commons/1.4/maven-scm-provider-svn-commons-1.4.jar,/Users/Frank/.m2/repository/regexp/regexp/1.3/regexp-1.3.jar,/Users/Frank/.m2/repository/dom4j/dom4j/1.6.1/dom4j-1.6.1.jar,/Users/Frank/.m2/repository/xml-apis/xml-apis/1.0.b2/xml-apis-1.0.b2.jar,/Users/Frank/.m2/repository/org/jsoup/jsoup/1.8.1/jsoup-1.8.1.jar,/Users/Frank/.m2/repository/commons-fileupload/commons-fileupload/1.3.1/commons-fileupload-1.3.1.jar,/Users/Frank/.m2/repository/commons-io/commons-io/2.4/commons-io-2.4.jar,/Users/Frank/.m2/repository/joda-time/joda-time/2.6/joda-time-2.6.jar,/Users/Frank/.m2/repository/com/google/code/gson/gson/2.3.1/gson-2.3.1.jar,/Users/Frank/.m2/repository/com/google/guava/guava/18.0/guava-18.0.jar,/Users/Frank/.m2/repository/com/googlecode/xmemcached/xmemcached/2.0.0/xmemcached-2.0.0.jar,/Users/Frank/.m2/repository/javax/mail/mail/1.4.1/mail-1.4.1.jar,/Users/Frank/.m2/repository/javax/mail/mail/1.4.1/activation.jar,/Users/Frank/.m2/repository/javax/activation/activation/1.1/activation-1.1.jar,/Users/Frank/.m2/repository/com/belerweb/pinyin4j/2.5.0/pinyin4j-2.5.0.jar,/Users/Frank/.m2/repository/org/jdom/jdom/2.0.2/jdom-2.0.2.jar,/Users/Frank/.m2/repository/org/apache/poi/poi-scratchpad/3.10.1/poi-scratchpad-3.10.1.jar,/Users/Frank/.m2/repository/org/apache/poi/poi/3.11/poi-3.11.jar,/Users/Frank/.m2/repository/org/springframework/spring-core/4.1.4.RELEASE/spring-core-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/springframework/spring-context/4.1.4.RELEASE/spring-context-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/springframework/spring-aop/4.1.4.RELEASE/spring-aop-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/aopalliance/aopalliance/1.0/aopalliance-1.0.jar,/Users/Frank/.m2/repository/org/springframework/spring-beans/4.1.4.RELEASE/spring-beans-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/springframework/spring-expression/4.1.4.RELEASE/spring-expression-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/springframework/spring-context-support/4.1.4.RELEASE/spring-context-support-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/springframework/spring-webmvc/4.1.4.RELEASE/spring-webmvc-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/springframework/spring-web/4.1.4.RELEASE/spring-web-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/springframework/spring-jdbc/4.1.4.RELEASE/spring-jdbc-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/springframework/spring-tx/4.1.4.RELEASE/spring-tx-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/springframework/spring-orm/4.1.4.RELEASE/spring-orm-4.1.4.RELEASE.jar,/Users/Frank/.m2/repository/org/aspectj/aspectjweaver/1.8.4/aspectjweaver-1.8.4.jar,/Users/Frank/.m2/repository/org/hibernate/hibernate-core/4.3.7.Final/hibernate-core-4.3.7.Final.jar,/Users/Frank/.m2/repository/org/jboss/logging/jboss-logging/3.1.3.GA/jboss-logging-3.1.3.GA.jar,/Users/Frank/.m2/repository/org/jboss/logging/jboss-logging-annotations/1.2.0.Beta1/jboss-logging-annotations-1.2.0.Beta1.jar,/Users/Frank/.m2/repository/org/jboss/spec/javax/transaction/jboss-transaction-api_1.2_spec/1.0.0.Final/jboss-transaction-api_1.2_spec-1.0.0.Final.jar,/Users/Frank/.m2/repository/org/hibernate/common/hibernate-commons-annotations/4.0.5.Final/hibernate-commons-annotations-4.0.5.Final.jar,/Users/Frank/.m2/repository/org/hibernate/javax/persistence/hibernate-jpa-2.1-api/1.0.0.Final/hibernate-jpa-2.1-api-1.0.0.Final.jar,/Users/Frank/.m2/repository/org/javassist/javassist/3.18.1-GA/javassist-3.18.1-GA.jar,/Users/Frank/.m2/repository/antlr/antlr/2.7.7/antlr-2.7.7.jar,/Users/Frank/.m2/repository/org/jboss/jandex/1.1.0.Final/jandex-1.1.0.Final.jar,/Users/Frank/.m2/repository/org/hibernate/hibernate-entitymanager/4.3.7.Final/hibernate-entitymanager-4.3.7.Final.jar,/Users/Frank/.m2/repository/org/hibernate/hibernate-ehcache/4.3.7.Final/hibernate-ehcache-4.3.7.Final.jar,/Users/Frank/.m2/repository/org/hibernate/hibernate-validator/5.1.3.Final/hibernate-validator-5.1.3.Final.jar,/Users/Frank/.m2/repository/javax/validation/validation-api/1.1.0.Final/validation-api-1.1.0.Final.jar,/Users/Frank/.m2/repository/com/fasterxml/classmate/1.0.0/classmate-1.0.0.jar,/Users/Frank/.m2/repository/org/freemarker/freemarker/2.3.21/freemarker-2.3.21.jar,/Users/Frank/.m2/repository/net/sf/ehcache/ehcache-core/2.6.10/ehcache-core-2.6.10.jar,/Users/Frank/.m2/repository/com/alibaba/fastjson/1.2.4/fastjson-1.2.4.jar,/Users/Frank/.m2/repository/com/alibaba/druid/1.0.12/druid-1.0.12.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/../lib/jconsole.jar,/Library/Java/JavaVirtualMachines/jdk1.8.0_73.jdk/Contents/Home/jre/../lib/tools.jar,/Users/Frank/.m2/repository/mysql/mysql-connector-java/5.1.34/mysql-connector-java-5.1.34.jar,/Users/Frank/.m2/repository/com/microsoft/sqlserver/sqljdbc4/4.0/sqljdbc4-4.0.jar,/Users/Frank/.m2/repository/org/slf4j/slf4j-api/1.7.9/slf4j-api-1.7.9.jar,/Users/Frank/workspace-java/hnProjects/app-dao/target/app-dao-1.0-SNAPSHOT.jar,/Users/Frank/workspace-java/hnProjects/app-service/target/app-service-1.0-SNAPSHOT.jar,/Users/Frank/.m2/repository/javax/servlet/jsp/jstl/javax.servlet.jsp.jstl-api/1.2.1/javax.servlet.jsp.jstl-api-1.2.1.jar,/Users/Frank/.m2/repository/javax/el/javax.el-api/2.2.4/javax.el-api-2.2.4.jar,/Users/Frank/.m2/repository/javax/servlet/javax.servlet-api/3.1.0/javax.servlet-api-3.1.0.jar,/Users/Frank/.m2/repository/javax/servlet/jsp/javax.servlet.jsp-api/2.3.1/javax.servlet.jsp-api-2.3.1.jar,.]  致命错误: 在类路径或引导类路径中找不到程序包 java.lang  [INFO] -------------------------------------------------------------  [ERROR] COMPILATION ERROR :   [INFO] -------------------------------------------------------------  [ERROR] An unknown compilation problem occurred  [INFO] 1 error  [INFO] -------------------------------------------------------------  [INFO] ------------------------------------------------------------------------  [INFO] Reactor Summary:  [INFO]   [INFO] Projects :: APP :: Parent ........................... SUCCESS [  0.357 s]  [INFO] Projects :: APP :: Utils ............................ SUCCESS [  1.257 s]  [INFO] Projects :: APP :: Configs .......................... SUCCESS [  0.374 s]  [INFO] Projects :: APP :: Dao .............................. SUCCESS [  0.172 s]  [INFO] Projects :: APP :: Service .......................... SUCCESS [  0.152 s]  [INFO] Projects :: APP :: Admin ............................ SUCCESS [  1.273 s]  [INFO] Projects :: APP :: Web .............................. FAILURE [  0.081 s]  [INFO] xxx ................................................. SKIPPED  [INFO] ------------------------------------------------------------------------  [INFO] BUILD FAILURE  [INFO] ------------------------------------------------------------------------  [INFO] Total time: 5.426 s  [INFO] Finished at: 2016-07-22T21:26:15+08:00  [INFO] Final Memory: 39M/310M  [INFO] ------------------------------------------------------------------------  [ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.2:compile (default-compile) on project app-web: Compilation failure  [ERROR] An unknown compilation problem occurred  [ERROR] -> [Help 1]  [ERROR]   [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.  [ERROR] Re-run Maven using the -X switch to enable full debug logging.  [ERROR]   [ERROR] For more information about the errors and possible solutions, please read the following articles:  [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException  [ERROR]   [ERROR] After correcting the problems, you can resume the build with the command  [ERROR]   mvn  -rf :app-web

原因

原因在于 compiler 插件的配置。


 <plugin>   
<groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-compiler-plugin</artifactId>   <version>${maven.compiler.version}</version>
   <configuration>     
<source>${java.version}</source>
     <target>${java.version}</target>     <encoding>${project.build.sourceEncoding}</encoding>     <showWarnings>true</showWarnings>     
<compilerArguments>       
<verbose />      
 <!-- 这个配置很特殊：windows下使用分号（;）分隔，linux/mac下使用冒号（:）分隔 -->       <bootclasspath>${java.home}/lib/rt.jar;${java.home}/lib/jce.jar</bootclasspath>     </compilerArguments>   
</configuration> 
 </plugin>  <!-- ... -->  配置中14行的分隔符问题，在windows下使

配置中分隔符问题，在windows下使用maven 应该使用分号（;）分隔，linux/mac 下使用（:）分隔。

发布于

@RequestParam注解的详细介绍

@RequestParam （org.springframework.web.bind.annotation.RequestParam）用于将指定的请求参数赋值给方法中的形参。

有三个属性：

  （1）value：请求参数名（必须配置）

（2）required：是否必需，默认为 true，即 请求中必须包含该参数，如果没有包含，将会抛出异常（可选配置）

（3）defaultValue：默认值，如果设置了该值，required 将自动设为 false，无论你是否配置了required，配置了什么值，都是 false（可选配置）

　　　 1为演示效果，首先需要创建一个测试控制类，然后创建一个测试方法，如图所示，方法里添加一个参数，此时方法参数没有添加注解

  1.  
  2. 通过idea工具启动web项目，然后通过浏览器访问测试效果，不带参数则获取的参数为null，但页面可以正常显示，请求可以正常的执行。 带上参数之后，参数可以正常的获取并打印出来了
  3.  下面来对比下添加注解的效果，但只是添加@RequestParam，没有带任何的注解设置参数。 
  4. 再次通过浏览器访问查看效果，此时带上userName参数页面可以正常显示并打印出结果值，但如图所示，不带参数的时候，页面报错，返回400，并提示userName不存在 
  5.  当然这样的限制是可以选择的，@RequestParam里添加required=false来关闭必须参数的限制，这样就和第一种不带注解的效果一样了 
  6.  @RequestParam还可以在参数为空的情况下，为我们设置一个参数的默认值，如图所示，可以看出来，没有参数的情况下，获取到的就是默认值 
  7.  默认参数的key名称是方法里的参数名称，但通过@RequestParam可以自定义另外一个，因为在某些条件下，方法名称固定下来不可以修改了，但请求的参数又需要通过另外一个参数key名称来传递，这样就可以通过这样的方式来实现
@RequestParam String inputStr  
// 下面的对传入参数指定为aa，如果前端不传aa参数名，会报错  
@RequestParam(value="aa") String inputStr

发布于

StandardCharsets jdk自带的字符编码常量字段

用StandardCharsets.UTF_8 返回”UTF-8″这个字符

public final class StandardCharsets {

    private StandardCharsets() {
        throw new AssertionError("No java.nio.charset.StandardCharsets instances for you!");
    }
    /**
     * Seven-bit ASCII, a.k.a. ISO646-US, a.k.a. the Basic Latin block of the
     * Unicode character set
     */
    public static final Charset US_ASCII = Charset.forName("US-ASCII");
    /**
     * ISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1
     */
    public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
    /**
     * Eight-bit UCS Transformation Format
     */
    public static final Charset UTF_8 = Charset.forName("UTF-8");
    /**
     * Sixteen-bit UCS Transformation Format, big-endian byte order
     */
    public static final Charset UTF_16BE = Charset.forName("UTF-16BE");
    /**
     * Sixteen-bit UCS Transformation Format, little-endian byte order
     */
    public static final Charset UTF_16LE = Charset.forName("UTF-16LE");
    /**
     * Sixteen-bit UCS Transformation Format, byte order identified by an
     * optional byte-order mark
     */
    public static final Charset UTF_16 = Charset.forName("UTF-16"); 
}

直接用

@Test
    public void testUTF8() {
        System.out.println(StandardCharsets.UTF_8.name()); //UTF-8
    }