Hibernate异常：Unable to locate appropriate constructor on class
1.这是Hibernate实体类操作异常，出现这个异常，要检查以下几个情况。
2.首先要检查在实体类中是否有构造器，例如：
public class PropertyStock {private String stockName;
private Double stockPriceNow;
private long num;//持有股票总数
private long numDunjie;//冻结数量
private Double price;//成交价钱
private String stockCode;//股票代码
private long customerId;
//默认构造方法
public PropertyStock() {}
//有参数的构造方法, 返回的结果中有几个变量，就写几个变量的构造方法。
public PropertyStock(Double stockPriceNow,String stockName,long num,long numDunjie,Double price ) {
this.stockName=stockName;
this.stockPriceNow=stockPriceNow;
this.num=num;
this.numDunjie=numDunjie;
this.price=price;
}
public String getStockName() {
return stockName;
}
public void setStockName(String stockName) {
this.stockName = stockName;
}
public Double getStockPriceNow() {
return stockPriceNow;
}
public void setStockPriceNow(Double stockPriceNow) {
this.stockPriceNow = stockPriceNow;
}
public long getNum() {
return num;
}
public void setNum(long num) {
this.num = num;
}
public long getNumDunjie() {
return numDunjie;
}
public void setNumDunjie(long numDunjie) {
this.numDunjie = numDunjie;
}
public Double getPrice() {
return price;
}
public void setPrice(Double price) {
this.price = price;
}
public String getStockCode() {
return stockCode;
}
public void setStockCode(String stockCode) {
this.stockCode = stockCode;
}
public long getCustomerId() {
return customerId;
}
public void setCustomerId(long customerId) {
this.customerId = customerId;
}
}
3.如果有上面两个构造器，再检查变量是否匹配，不要写错了
4.然后要注意，变量类型是否匹配，比如，上面的age变量类型为：Integer，写成 int可能会有问题。所以要注意long和Long，boolean和Boolean等等，最好写成long型
5.查询时有几个参数，你的构造器要对应相应的参数public List<PropertyStock> findByCustomerId(java.lang.Long customerid){
String hql="select new com.stock.model.PropertyStock(TS.stockPriceNow,TS.stockName,TP.num,TP.numDunjie,TP.price) from TStock as TS,TProperty as TP where TS.stockCode=TP.stockCode and TP.customerId=?";
List<PropertyStock> list = getHibernateTemplate().find(hql, customerid);
System.out.println("查询的结果长度为："+list.size());
// Query query = session.createQuery(hql);
// query.setLong(0, customerid);
// List<PropertyStock> list = query.list();
// System.out.println("长度为："+list.size());
System.out.println(list.get(0).getCustomerId());
System.out.println(list.get(0).getNum());
System.out.println(list.get(0).getNumDunjie());
System.out.println(list.get(0).getPrice());
System.out.println(list.get(0).getStockPriceNow());
return list;
}
上面的hql语句对应的sql语句为：select t_stock.stock_price_now,t_stock.stock_name,t_property.num,t_property.num_dunjie,t_property.price from t_stock,t_property where t_property.customer_id=1 and t_stock.stock_code=t_property.stock_code
查询两种表中的部分属性，其中条件是stockcode相等，且customerid=1；