如何使用Spring JPA在请求中订购接收参数的流

huangapple
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英文:

How to order a stream receiving parameter in the request using spring JPA

问题

  1. public List<BillToPay> findWithOrderBy(String orderName, String orderDir) {
  2.     List<BillToPay> listBillToPay = this.repository.findAll(Sort.by(orderDir.equals("ASC") ? Sort.Direction.ASC : Sort.Direction.DESC, orderName));
  3. }
英文:

I need to order the stream from the parameters received above, how can I do this safely and that it works in an ASC and DESC way?

  1. public List&lt;BillToPay&gt; findWithOrderBy(String orderName, String orderDir) {
  2.     List&lt;BillToPay&gt; listBillToPay = this.repository.findAll();
  3. }

答案1

得分: 0

  1. 不需要为此创建流，因为Spring Data JPA已经有重载的方法允许排序。您只需要将参数转换为必要的类型，例如：
  3.     //在这里传递要按其排序的字段的名称，而不是实际值
  4.     public List<BillToPay> findWithOrderBy(String fieldName, String direction) {
  5.         Sort.Direction dir = direction.equalsIgnoreCase("asc") ? Sort.Direction.ASC 
  6.                 : Sort.Direction.DESC;
  7.         List<BillToPay> listBillToPay = this.repository.findAll(Sort.by(dir, fieldName));
  8.         return listBillToPay;
  9.     }
  11. JPA方法接受一个可变的字符串参数，因此假设您想按相同方向排序多个字段（不是ASC/DESC混合），您可以轻松实现它并几乎不改变任何内容。
  13.     //方向必须首先出现，因为变量参数必须出现在签名的最后
  14.     public List<BillToPay> findWithOrderBy(String direction, String...fieldNames) {
  15.         Sort.Direction dir = direction.equalsIgnoreCase("asc") ? Sort.Direction.ASC 
  16.                 : Sort.Direction.DESC;
  17.         List<BillToPay> listBillToPay = this.repository.findAll(Sort.by(dir, fieldNames));
  18.         return listBillToPay;
  19.     }
英文:

You don't need a stream for this as Spring Data JPA already has overloaded methods that allow sorting. You just need to convert your arguments to the necessary type such as:

  1. //Pass the name of the field you want to sort by here, not the actual value
  2. public List&lt;BillToPay&gt; findWithOrderBy(String fieldName, String direction) {
  3.     Sort.Direction dir = direction.equalsIgnoreCase(&quot;asc&quot;) ? Sort.Direction.ASC 
  4.             : Sort.Direction.DESC;
  5.     List&lt;BillToPay&gt; listBillToPay = this.repository.findAll(Sort.by(dir, fieldName));
  6.     return listBillToPay;
  7. }

The JPA method accepts a variable String argument, so assuming you want to sort by multiple fields all in the same direction (not a mix of ASC/DESC) you could easily implement it and barely change anything.

  1. //Direction needs to come first as variable parameter must come last in the signature
  2. public List&lt;BillToPay&gt; findWithOrderBy(String direction, String...fieldNames) {
  3.     Sort.Direction dir = direction.equalsIgnoreCase(&quot;asc&quot;) ? Sort.Direction.ASC 
  4.             : Sort.Direction.DESC;
  5.     List&lt;BillToPay&gt; listBillToPay = this.repository.findAll(Sort.by(dir, fieldNames));
  6.     return listBillToPay;
  7. }

huangapple
  • 本文由 发表于 2023年3月7日 22:59:06
  • 转载请务必保留本文链接：https://go.coder-hub.com/75663625.html
  • java
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