把一个Model对象转化成SQL语句，model对象sql语句,package com.

把一个Model对象转化成SQL语句，model对象sql语句,package com.

package com.xxtiandi.util;import java.lang.reflect.Field;import java.util.logging.Logger;public class ModelToSQL {    public static final int INSERTSQL = 1;    public static final int UPDATESQL = 2;    private static Logger log = Logger.getLogger(ModelToSQL.class.getName());    /**     * 获取InsertSQL     *      * @param model     * @return     */    public static String getInsertSQL(Object model) {        if (model == null) {            log.info("传入参数为null！！");            throw new NullPointerException();        }        return getInsertOrUpdateSQL(INSERTSQL, model);    }    /**     * 获取UpdateSQL     *      * @param model     * @return     */    public static String getUpdateSQL(Object model) {        if (model == null) {            log.info("传入参数为null！！");            throw new NullPointerException();        }        return getInsertOrUpdateSQL(UPDATESQL, model);    }    /**     * 选择Insert或者Update语句,如果是UPDATE，则是可传参的根据ID更新     *      * @param type     * @param model     * @return     */    private static String getInsertOrUpdateSQL(int type, Object model) {        String sql = null;        StringBuilder sb1 = new StringBuilder();        StringBuilder sb2 = new StringBuilder();        Class<?> cl = model.getClass();        Field[] fields = cl.getDeclaredFields();        String table = cl.getSimpleName();        try {            for (Field field : fields) {                field.setAccessible(true);                if (type == 1) {                    sb1.append(",");                    sb1.append(field.getName());                    if (field.getType().equals(String.class)) {                        String value = (String) field.get(model);                        sb2.append(",");                        sb2.append("'");                        sb2.append(value);                        sb2.append("'");                    } else if (field.getType().equals(int.class)) {                        int value = field.getInt(model);                        sb2.append(",");                        sb2.append(value);                    }                } else if (type == 2) {                    if (field.getType().equals(String.class)) {                        String value = (String) field.get(model);                        sb1.append(",");                        sb1.append(field.getName());                        sb1.append("='");                        sb1.append(value);                        sb1.append("'");                    } else if (field.getType().equals(int.class)) {                        int value = field.getInt(model);                        sb1.append(",");                        sb1.append(field.getName());                        sb1.append("=");                        sb1.append(value);                    }                }            }        } catch (IllegalArgumentException e) {            e.printStackTrace();        } catch (IllegalAccessException e) {            e.printStackTrace();        }        if (type == 1) {            sql = String.format("insert into %s (%s) values(%s)", table,                    sb1.substring(1), sb2.substring(1));        } else if (type == 2) {            sql = String.format("update %s set %s where %s=?", table,                    sb1.substring(1), fields[0].getName());        }        log.info("执行语句：" + sql);        return sql;    }    /**     * 获取DeleteSQL,需要传ID值     *      * @param model     * @return     */    public static String getDeleteSQL(Object model) {        String sql = null;        Class<?> cl = model.getClass();        Field[] fields = cl.getDeclaredFields();        String table = cl.getSimpleName();        sql = String.format("delete from %s where %s=?", table,                fields[0].getName());        log.info("执行语句：" + sql);        return sql;    }    /**     * 获取DeleteSQL     *      * @param table     * @param primkey     * @return     */    public static String getDeleteSQL(String table, String primkey) {        String sql = String.format("delete from %s where %s=?", table, primkey);        log.info("执行语句：" + sql);        return sql;    }    /**     * 根据ID查询     *      * @param table     * @param primkey     * @param id     * @return     */    public static String getQueryByIdSQL(String table, String primkey) {        String sql = null;        sql = String.format("select * from %s where %s = ?", table, primkey);        log.info("执行语句：" + sql);        return sql;    }    /**     * 获取查询所有记录的SQL     *      * @param model     * @param OrderBy     * @return     */    public static String getQueryAllSQL(Object model, String orderBy) {        if (model == null) {            log.info("传入参数为null！！");            throw new NullPointerException();        }        String sql = null;        Class<?> cl = model.getClass();        String table = cl.getSimpleName();        sql = String.format("select * from %s order by %s", table, orderBy);        log.info("执行语句：" + sql);        return sql;    }    /**     * 分页按条件查询     *      * @param model     * @param selections     *            为null是默认为全部     * @param where     *            为null是为无条件分页查询     * @param limit     * @param page     * @param orderBy     *            null为不排序     * @return     */    public static String getQuery(Object model, String selections,            String where, int limit, int page, String orderBy) {        if (model == null) {            log.info("传入参数为null！！");            throw new NullPointerException();        }        String sql = null;        Class<?> cl = model.getClass();        String table = cl.getSimpleName();        int start = limit * page;        if (selections == null) {            selections = "*";        }        if (where == null) {            if (orderBy == null) {                sql = String.format("select %s from %s limit %s,%s",                        selections, table, start, limit);            } else {                sql = String.format(                        "select %s from %s order by %s limit %s,%s",                        selections, table, orderBy, start, limit);            }        } else {            if (orderBy == null) {                sql = String                        .format("select *  from (select %s from %s where %s) %s limit %s,%s",                                selections, table, where, table, start, limit);            } else {                sql = String                        .format("select *  from (select %s from %s where %s) %s order by %s limit %s,%s",                                selections, table, where, table, start, limit);            }        }        log.info("执行语句:" + sql);        return sql;    }}//该片段来自于http://byrx.net