spring中jdbcTemplate.batchUpdate的几种使用情况

public void a (){
        try {
            String[] sql = new String[4];
            sql[0] = "insert into TEST(id) values (1)";
            sql[1] = "insert into TEST(id) values (2)";
            sql[2] = "insert into TEST(id) values (1)";
            sql[3] = "insert into TEST(id) values (3)";
            jdbcTemplate.batchUpdate(sql);
        } catch (DataAccessException e) {
            e.printStackTrace();
        }
}

public void b (){
        try {
            String sql = "insert into TEST(id) values (?)";
            List<Object[]> list = new ArrayList<>();
            for (int i = 0; i < 4; i++) {
                String[] sqls = new String[1];
                sqls[0] = i +"";
                if(i == 2){ // 增加一条异常数据
                    sqls[0] = i-1 +"";
                }
                list.add(sqls);
            }
            jdbcTemplate.batchUpdate(sql,list);
        } catch (DataAccessException e) {
            e.printStackTrace();
        }
    }

public void b (){
        try {
            String[] sql = new String[2];
            sql[0] = "insert into TEST(id) values (1)";
            sql[1] = "insert into TEST(id) " +
                           "select '1' from dual where not EXISTS(SELECT id FROM TEST WHERE id = '1')";
            sql[2] = "insert into TEST(id) values (2)";
            jdbcTemplate.batchUpdate(sql);
        } catch (DataAccessException e) {
            e.printStackTrace();
        }
    }