带有 where 选项的 java mysqldump

Question

我尝试使用这个代码，它适用于 linux 命令行，在 java 下

mysqldump --where="date>='20180201' AND date<='20180228'" -uuser -ppassword --skip-add-drop-table --no-create-info --no-create-db -B mydb --tables table1 -r /root/Documents/DbBackup/table1.sql

为了使其在 java 中工作，我使用以下代码：

public static boolean backupDB(String dbName, String where_filter, String path, String tableName) {
    String executeCmd = "mysqldump --where="+where_filter+" -u" + userName + " -p" + password + " --skip-add-drop-table --no-create-info --no-create-db "+" -B " + dbName +" "+tableName+" -r " + path;

    System.out.println("backupDB "+executeCmd);
    Process runtimeProcess;
    try {

        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) {            

    }

    return false;
}

如果调用在 java 代码中，则相同的命令行指令不起作用。我哪里错了？是否可以将错误日志重定向到文件？

如果我使用 where 子句--where=date='20180206' 它也适用于 java。

Answer 1

命令中的参数太多。我认为您应该使用ProcessBuilder 而不是Runtime.exec。它将命令和参数作为一个数组，这种方式更安全恕我直言。所以试试这个代码：

String[] executeCmd = new String[]{
    "mysqldump", "--where=" + where_filter, "-u" + userName, "-p" + password, 
    "--skip-add-drop-table", "--no-create-info", "--no-create-db", "-B", dbName, 
    "--tables", tableName, "--result-file=" + path
};
ProcessBuilder builder = new ProcessBuilder(executeCmd);
builder.redirectErrorStream(true);
Process runtimeProcess;
try {

    runtimeProcess = builder.start();
    InputStream processInputStream = process.getInputStream();
    int processComplete = runtimeProcess.waitFor();
    if (processComplete == 0) {
        System.out.println("Backup created successfully");
        return true;
    } else {
        System.out.println("Could not create the backup");                
    }
    BufferedReader reader = new BufferedReader(new InputStreamReader(processInputStream));
    System.out.println("output: ");
        while (reader.ready()) {
            System.out.println(reader.readLine());
        }
} catch (Exception ex) {

}
return false;

还可以尝试编写带有完整路径的mysqldump 命令，如/usr/bin/mysqldump，如果适用于此，则mysqldump 命令不在路径中。