HibernateCRUD基础框架(2)-HQL语句构造器(HqlQueryBuilder,HqlUpdateBuilder)

上篇讲述了最基本的实体类，本篇接着讲述HQL语句构造器，包括查询和更新等。

优点：通过面向对象的方式构造HQL语句，更快捷，不需要手动拼接HQL。

缺点：封装可能降低性能，只能支持常用的和较为简单的HQL构造。

            部分功能不完善，待开发。

1.HQL语句构造器

package cn.fansunion.hibernate.sql;import org.apache.commons.lang.text.StrBuilder;import cn.fansunion.hibernate.sql.entity.From;import cn.fansunion.hibernate.sql.entity.GroupBy;import cn.fansunion.hibernate.sql.entity.OrderGroup;import cn.fansunion.hibernate.sql.entity.SearchCondition;/** * HQL语句构造器。 * <p/> * 目前只适用于1张表的情况，只有查询条件支持占位符，建议使用完全构造的sql语句（是否会产生sql注入，待研究）。 * * @author [e-mail] */public class HqlQueryBuilder extends ConstantBase {    // 查询条件组合策略    // -----------------------------------    // *************From******************    // -----------------------------------    private String select;    private From from;    // -----------------------------------    // *************Where******************    // -----------------------------------    private SearchCondition searchCondition;    // -----------------------------------    // *************Group by**************    // -----------------------------------    private GroupBy groupBy;    // -----------------------------------    // *************Order by******************    // -----------------------------------    private OrderGroup orderGroup;    // -----------------------------------    // 通过构造方法，创建查询构造器。各种字段组合形式的构造方法太多，只给出3种比较常见的。    // 建议使用链式构造或setter方法设置属性。    // -----------------------------------    public HqlQueryBuilder() {    }    public HqlQueryBuilder(From from) {        this.from = from;    }    public HqlQueryBuilder(From from, SearchCondition searchCondition,            GroupBy groupBy, OrderGroup orderGroup) {        this.from = from;        this.searchCondition = searchCondition;        this.groupBy = groupBy;        this.orderGroup = orderGroup;    }    public HqlQueryBuilder select(String select) {        this.select = select;        return this;    }    // -----------------------------------    // 支持链式用法,暂时不能很好地支持**************    // -----------------------------------    public HqlQueryBuilder from(From from) {        this.from = from;        return this;    }    public HqlQueryBuilder from(String model) {        doFrom(model, "");        return this;    }    public HqlQueryBuilder from(String model, String alias) {        doFrom(model, alias);        return this;    }    public HqlQueryBuilder from(Class<?> clazz) {        doFrom(clazz.getSimpleName());        return this;    }    public HqlQueryBuilder from(Class<?> clazz, String alias) {        doFrom(clazz.getSimpleName(), alias);        return this;    }    private void doFrom(String model) {        doFrom(model, null);    }    private void doFrom(String model, String alias) {        this.from = new From(model, alias);    }    public HqlQueryBuilder searchCodition(SearchCondition searchCondition) {        this.searchCondition = searchCondition;        return this;    }    public HqlQueryBuilder groupBy(GroupBy groupBy) {        this.groupBy = groupBy;        return this;    }    public HqlQueryBuilder orderBy(OrderGroup orderGroup) {        this.orderGroup = orderGroup;        return this;    }    /**     * 转换成HQL语句     */    public String toHql() {        StrBuilder builder = new StrBuilder();        if (select != null) {            builder.append(select).append(EMPTY);        }        if (from != null) {            builder.append(from);        }        if (searchCondition != null) {            builder.append(searchCondition);        }        if (groupBy != null) {            builder.append(groupBy);        }        if (orderGroup != null) {            builder.append(orderGroup);        }        return builder.toString();    }}

2.Hql更新语句构造器

下面这个是构造更新HQL语句的构造器，待完善。

package cn.fansunion.hibernate.sql.update;import java.util.HashMap;import java.util.Map;import cn.fansunion.hibernate.util.Pair;/** * Hql更新语句构造器。（TODO 待完善） * * @author [e-mail] */public class HqlUpdateBuilder {    private Map<String, Object> params;    private String model;    public HqlUpdateBuilder() {        params = new HashMap<String, Object>();    }    public HqlUpdateBuilder(String model) {    }    public HqlUpdateBuilder(Class<?> model) {        this.model = model.getSimpleName();    }    public HqlUpdateBuilder model(String model) {        this.model = model;        return this;    }    public HqlUpdateBuilder model(Class<?> model) {        this.model = model.getSimpleName();        return this;    }    public HqlUpdateBuilder param(String key, Object value) {        params.put(key, value);        return this;    }    public HqlUpdateBuilder param(Pair... pair) {        for (Pair p : pair) {            params.put(p.getKey(), p.getValue());        }        return this;    }    public HqlUpdateBuilder param(Map<String, Object> params) {        this.params.putAll(params);        return this;    }    public String toHql() {        String hql = "update " + model + " set ";        for (Map.Entry<String, Object> entry : params.entrySet()) {            String key = entry.getKey();            hql += key + "=:" + key + " ";        }        return hql;    }}

3.原生SQL语句构造器

类似的，有时候，可能不用Hibernate的HQL，而是用原生的SQL。

这个时候，可以编写与HqlQueryBuilder和HqlUpdateBuilder相应的SQL版本。

package cn.fansunion.hibernate.sql;import cn.fansunion.hibernate.sql.entity.Limit;/** * 原生SQL语句构造器。（TODO 待完善） * * @author [e-mail] */public class SqlQueryBuilder {    // limit只适用于nativeSQL    // -----------------------------------    // *************limit**************    // -----------------------------------    private Limit limit;        /**     * 转换成SQL语句     */        public String toSql(){        //TODO        return null;    }}

4.HQL查询构造器使用例子

/** * HQL查询构造器使用例子。 * * @author [e-mail] */public class HqlQueryBuilderTest extends ConstantBase {    @Test    public void test() {        From from = new From(HqlQueryBuilder.class);        SearchCondition searchCondition = createSearchCondtion();        OrderGroup orderGroup = createOrderGroup();        GroupBy groupBy = createGroupBy();        HqlQueryBuilder builder = new HqlQueryBuilder(from, searchCondition,                groupBy, orderGroup);        // 直接打印，不使用“断言”        println(builder.toHql());    }    private GroupBy createGroupBy() {        GroupBy groupBy = new GroupBy();        groupBy.addGroup("name");        groupBy.addGroup("id");        return groupBy;    }    private OrderGroup createOrderGroup() {        Order order1 = new Order("id", false);        Order order2 = new Order("name", "asc");        OrderGroup orderGroup = new OrderGroup(order1, order2);        return orderGroup;    }    private SearchCondition createSearchCondtion() {        GroupCondition groupCondition1 = oneGroupCondition();        GroupCondition groupCondition2 = oneGroupCondition();        //String groupStr1 = groupCondition1.toString();        //String groupStr2 = groupCondition2.toString();        // System.out.println(groupStr1);        // System.out.println(groupStr2);        SearchCondition searchCondition = new SearchCondition();        searchCondition.addGroupCondition(groupCondition1);        searchCondition.addGroupCondition(groupCondition2, true);        //String searchStr = searchCondition.toString();        // System.out.println(searchStr);        return searchCondition;    }    private GroupCondition oneGroupCondition() {        // =,Integer        String age = "age";        Integer ageValue = 24;        Condition condition2 = new Condition(age, Operator.EQUALS, ageValue);        String str2 = condition2.toString();        Assert.assertEquals(str2, age + EQUALS_WITH_BLANK + ageValue);        // =,String        String name = "name";        String nameValue = "[e-mail]";        Condition condition = new Condition(name, Operator.EQUALS, nameValue);        String str = condition.toString();        Assert.assertEquals(str, name + EQUALS_WITH_BLANK                + buildQuota(nameValue));        // =,Date        String date = "date";        Date dateValue = new Date();        Condition condition3 = new Condition(date, Operator.EQUALS, dateValue);        String str3 = condition3.toString();        Assert.assertEquals(str3, date + EQUALS_WITH_BLANK                + buildQuota(dateValue));        GroupCondition groupCondition1 = new GroupCondition();        groupCondition1.addCondition(condition);        groupCondition1.addCondition(condition2, true);        groupCondition1.addCondition(condition3, false);        return groupCondition1;    }}

5.输出结果

from HqlQueryBuilder where (name = '[e-mail]' or age = 24 and date = 'Mon Dec 30 16:57:21 CST 2013')

or (name = '[e-mail]' or age = 24 and date = 'Mon Dec 30 16:57:21 CST 2013')

group by name,id order by id desc,name asc

原文链接：http://blog.fansunion.cn/articles/3622(小雷博客-blog.fansunion.cn)