java 删除mysql所有外键，保留原有外键索引

1. 先导出数据库为.sql文件
2. 在程序中指定输入和输出位置
3. 运行
4. 将生成log.sql导入回数据库

import java.io.*;


public class DeleteForeignKey {
    public static void main(String[] args) {
        int n = -1;
        byte[] a = new byte[100];
        StringBuilder stringBuilder = new StringBuilder();
        FileOutputStream fos = null;
        try {
            //输入文件位置
            File f = new File("D:\笔记\work\test", "test.sql");
            //输出文件位置，true表示在文件末尾追加
            fos = new FileOutputStream("D:/log.sql",true);
            InputStream in = new FileInputStream(f);
            while ((n = in.read(a, 0, 100)) != -1) {
                String s = new String(a, 0, n);
                stringBuilder.append(s);
//                System.out.print(s);
            }
            in.close();
            String[] strings = stringBuilder.toString().split("n");
            for (int i = 0; i < strings.length - 1; i++) {
                if (strings[i].contains("CONSTRAINT") && strings[i].contains("FOREIGN KEY")) {
                    continue;
                }
                if (strings[i + 1].contains("CONSTRAINT") && strings[i + 1].contains("FOREIGN KEY")) {
                    strings[i].replace(",", "");
//                    System.out.println(strings[i]);
                    fos.write((strings[i]+"n").replace(",","").getBytes());
                } else {
                    fos.write((strings[i]+"n").getBytes());
//                    System.out.println(strings[i]);
                }
            }
            if (strings[strings.length - 1].contains("CONSTRAINT") && strings[strings.length - 1].contains("FOREIGN KEY")) {

            }else {
                fos.write((strings[strings.length - 1]+"n").getBytes());
//                System.out.println(strings[strings.length - 1]);
            }
            fos.close();
        } catch (IOException e) {
            System.out.println("File read Error" + e);
        }
    }
}