我尝试运行以下代码来创建 数据库备份, 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) ,并且它可以正常工作 。
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
请检查您的Global PATH环境变量是否在其中包含 \ bin(执行echo %PATH%并查看)。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。
echo %PATH%
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:
如果您不在PATH环境变量中,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;