备份mysql数据库Java代码

2020年3月18日 12点热度 0条评论

我尝试运行以下代码,这是为数据库创建备份,但它显示了一些运行时错误。

但是,我尝试在mysql shell中运行 System.out.println()输出部分(在给定的代码中已对此进行了注释),它可以工作

它显示io文件问题。请有人帮助我。

package files; public class tableBackup_1 { public boolean tbBackup(String dbName,String dbUserName, String dbPassword, String path) { String executeCmd = "mysqldump -u " + dbUserName + " -p" + dbPassword + " --add-drop-database -B " + dbName + " -r " + path; Process runtimeProcess; try { System.out.println(executeCmd);//this out put works in mysql shell runtimeProcess = Runtime.getRuntime().exec(executeCmd); int processComplete = runtimeProcess.waitFor(); if (processComplete == 0) { System.out.println("Backup created successfully"); return true; } else { System.out.println("Could not create the backup"); } } catch (Exception ex) { ex.printStackTrace(); } return false; } public static void main(String[] args){ tableBackup_1 bb = new tableBackup_1(); bb.tbBackup("test","harin","1234","C:/Users/Master/Downloads/123.sql"); } } 
 mysqldump -u harin -p1234 --add-drop-database -B test -r C:/Users/Master/Downloads/123.sql java.io.IOException: Cannot run program "mysqldump": CreateProcess error=2, The system cannot find the file specified at java.lang.ProcessBuilder.start(ProcessBuilder.java:460) at java.lang.Runtime.exec(Runtime.java:593) at java.lang.Runtime.exec(Runtime.java:431) at java.lang.Runtime.exec(Runtime.java:328) at files.tableBackup_1.tbBackup(tableBackup_1.java:12) at files.tableBackup_1.main(tableBackup_1.java:34) Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified at java.lang.ProcessImpl.create(Native Method) at java.lang.ProcessImpl.<init>(ProcessImpl.java:81) at java.lang.ProcessImpl.start(ProcessImpl.java:30) at java.lang.ProcessBuilder.start(ProcessBuilder.java:453) ... 5 more 

解决方案如下:

请检查您的Global PATH环境变量中是否包含 \ bin(执行 echo %PATH%来查看)。有效地,您应该能够在Plain DOS提示符下键入System.out.println()内容,并且应该能够运行它。

即使无法解决问题,也请尝试将代码更改为如下所示执行

runtimeProcess = Runtime.getRuntime().exec(new String[] { "cmd.exe", "/c", executeCmd });

理想情况下,这应该可以解决该问题。

更新:

如果您在PATH环境变量中没有它,请将代码更改为以下内容

String executeCmd = "<Path to MySQL>/bin/mysqldump -u " + dbUserName + " -p" + dbPassword + " --add-drop-database -B " + dbName + " -r " + path;