动态SQL拼接，select，insert的写法

import java.util.Iterator;
import java.util.Map;
import java.util.Set;

public class SQLUtil {
    public static String sqlSelect = "";

    public static String selectQuerySQL(Map<String, Object> map, String tableName) {
        if (map.isEmpty() || map.size() == 0) {
            sqlSelect = "select*from" + tableName;
        } else {
            sqlSelect = "select*from" + tableName + "where";
            Set set = map.keySet();
            Iterator iterator = set.iterator();
            int index = 0;
            while (iterator.hasNext()) {
                String key = (String) iterator.next();
                Object value = map.get(key);
                if (value instanceof String) {
                    value = "'" + value + "'";
                }
                index++;
                if ((index == 1 && map.size() == 1) || map.size() == index) {
                    sqlSelect += key + "=" + value + " ";
                } else {
                    sqlSelect += key + "=" + value + " " + "and" + " ";
                }
            }
        }
        System.out.println("待执行的select SQL："+sqlSelect);
        return sqlSelect;
    }
    public static String insertSQL(Map<String,Object>map){
        Iterator<String> iterator = map.keySet().iterator();
        StringBuilder sqlTable=new StringBuilder("insert into");
        StringBuilder sqlKey=new StringBuilder("(");
        StringBuilder sqlVaule= new StringBuilder("value(");
        while (iterator.hasNext()){
            String key=iterator.next();
            if(map.get(key).toString()==null||map.get(key).toString().length()==0){
                iterator.remove();
            }else {
                if (key.equals("tableName")){
                    sqlTable.append(map.get(key));
                }else {
                    sqlKey.append(key+",");
                    sqlVaule.append(map.get(key)+",");
                }
            }
        }
        sqlTable.append(sqlKey.toString().substring(0,sqlKey.toString().lastIndexOf(","))+")").append(sqlVaule.toString().substring(0,sqlVaule.lastIndexOf(","))+")");
        String sql=sqlTable.toString();
        System.out.println("待执行的insert SQL："+sql);
        return sql;
    }
    /*此为以上方法的用法，可以忽略*/
    /*public static void main(String[] args) {
        //调用select的方法
        Map<String,Object> map=new HashMap<>();
        map.put("字段名","具体的值");
        String tableName="表名";
        System.out.println(selectQuerySQL(map,tableName).toString());
        //调用insert的方法
        Map<String,Object> map=new HashMap<>();
        map.put("字段名","具体的值");
        map.put("tableName","这里最后添加表名");
        String sql = insertSQL(map);
        PreparedStatement statment = connection.prepareStatement(sql);
        statment.execute(sql);//这里是执行SQL语句，需要借助JDBCUtil中的Connection得到connection
    }*/
}

 以上添加的方法有点小问题，改进一下：

　　// 添加的公共方法
    public static String insertSQL(Map<String, Object> map) {
        map.put("tableName", "huawei_data_after_conversionu");
        Iterator<String> iterator = map.keySet().iterator();
        StringBuilder sqlTable = new StringBuilder("insert into ");
        StringBuilder sqlKey = new StringBuilder("(");
        StringBuilder sqlVaule = new StringBuilder("value(");
        while (iterator.hasNext()) {
            String key = iterator.next();
            if (map.get(key).toString() == null || map.get(key).toString().length() == 0) {
                iterator.remove();
            } else {
                if (key.equals("tableName")) {
                    sqlTable.append(map.get(key));
                } else {
                    sqlKey.append(key + ",");
                    if (map.get(key) instanceof String) {
                        sqlVaule.append("'" + map.get(key) + "',");
                    } else {
                        sqlVaule.append(map.get(key) + ",");
                    }

                }
            }
        }
        sqlTable.append(sqlKey.toString().substring(0, sqlKey.toString().lastIndexOf(",")) + ")")
                .append(sqlVaule.toString().substring(0, sqlVaule.lastIndexOf(",")) + ")");
        String sql = sqlTable.toString();
        System.out.println("待执行的insert SQL：" + sql);
        return sql;
    }

    // 执行SQL方法
    @SuppressWarnings({ "static-access", "unused" })
    public void executeSql(Connection connection, Statement statement, String sql) throws SQLException {
        try {
            connection = jdbcUtil.getConnection();
            statement = connection.createStatement();
            if (connection == null) {
                return;
            }
            int count = statement.executeUpdate(sql);// 这里是执行SQL语句插入
            if (count > 0) {
                logger.info("实时数据插入成功");
            } else {
                logger.info("实时数据插入失败");
            }
        } catch (Exception e) {
            e.printStackTrace();
            System.err.println("发生异常情况，导致插入失败，请重试...........");
        } finally {
            jdbcUtil.CloseConnection(connection, statement, null);
        }
    }