Question

我想做一个简单的条件JPA查询，以从 bankAccountNumber 和 branchCode 获取BankTransactions列表。

我的案例是

获取（“12345678”，“123”）获取银行帐户 12345678 和分支 123 的所有交易
获取（null，“123”）获取所有银行帐户和分支机构的所有交易 123
get（null，null）获取所有交易

我已经编写了这段代码，但由于BooleanExpression没有初始值，所以看起来真的很臭。

我认为我误解了API。我该如何清理它？

（我误解了API吗？）

public Page<BankTransactions> get(
  @RequestParam(required = false) String bankAccountNumber,
  @RequestParam(required = false) String branchCode,
  Pageable pageable) {

  QBankTransactions q = QBankTransactions.bankTransactions;
  BooleanExpression expression = null;

  if (bankAccountNumber != null) {
    if (expression == null) {
      expression = q.bankAccountNumber.eq(bankAccountNumber);;
    } else {
      expression.and(q.bankAccountNumber.eq(bankAccountNumber));
    }
  }
  if (branchCode != null) {
    if (expression == null) {
      expression = q.branchCode.eq(branchCode);
    } else {
      expression.and(q.branchCode.eq(branchCode));
    }
  }
  if (expression != null) {
    Page<BankTransactions> response = repository.findAll(expression, pageable);
    return response;
  } else {
    Page<BankTransactions> response = repository.findAll(pageable);
    return response;
  }
}

Answer 1

简单地将谓词传递给method参数。 More info

public Page<BankTransactions> get(
  @QuerydslPredicate(root = BankTransactions.class) Predicate predicate,    
      Pageable pageable, @RequestParam MultiValueMap<String, String> parameters) {
    Page<BankTransactions> response = repository.findAll(predicate, pageable);
    return response;

}

Answer 2

这是我的解决方案，使用QueryDslPredicateExecutor（允许执行Predicate）＆amp; QueryDslBindings（允许路径特定绑定 - API）。

例如，如果我尝试查找＆＃34; FindMe＆＃34;使用＆＃34; ind＆＃34;或＆＃34; Ind＆＃34;它会在＆＃34; FindMe中正确返回两个实例中的结果。绑定不会被绑定在HTTPRequest的谓词上找不到。

public interface BankTransactionsRepository extends PagingAndSortingRepository<BankTransactions, Long>,                                             
QueryDslPredicateExecutor<BankTransactions>,                                                
QuerydslBinderCustomizer<QBankTransactions> {

  @Override
  default public void customize(QuerydslBindings bindings, 
                                QBankTransactions root) {
      bindings.bind(root.description).first((path, value) -> path.containsIgnoreCase(value));
      bindings.bind(root.template.code).first((path, value) -> path.containsIgnoreCase(value));
      bindings.bind(root.status).first((path, value) -> path.containsIgnoreCase(value));
      bindings.bind(root.processedDate).first((path, value) -> path.eq(value));
  }    
}

Answer 3

我真的不喜欢这个答案，但至少它让我的代码看起来更干净。我为每种数据类型添加了辅助方法（eq）。

至少我的代码是每个输入鉴别器一行。

public Page<BankTransactions> get(
  @RequestParam(required = false) String bankAccountNumber,
  @RequestParam(required = false) String branchCode,
  Pageable pageable) {

  QBankTransactions q = QBankTransactions.bankTransactions;
  BooleanExpression expression = null;

  expression = eq(bankAccountNumber, expression, q.bankAccountNumber);
  expression = eq(branchCode, expression, q.branchCode);

  if (expression != null) {
    Page<BankTransactions> response = repository.findAll(expression, pageable);
    return response;
  } else {
    Page<BankTransactions> response = repository.findAll(pageable);
    return response;
  }
}

private BooleanExpression eq(String inputString, BooleanExpression expression, StringPath path) {
  if (inputString != null) {
    if (expression == null) {
      expression = path.eq(inputString);
    } else {
      expression.and(path.eq(inputString));
    }
  }
  return expression;
}

private BooleanExpression eq(Long inputLong, BooleanExpression expression, NumberPath path) {
  if (inputLong != null) {
    if (expression == null) {
      expression = path.eq(inputLong);
    } else {
      expression.and(path.eq(inputLong));
    }
  }
  return expression;
}

将QueryDSL链接到restful get的简单方法

3 个答案: