如何解决"Mapper method has an unsupported return type"

Question

我得到以下错误:

Mapper方法' nutrition .api.infrastructure.datasource.client. clientmapper。saveClient'有一个不支持的返回类型:class nutrition .api.domain.model. client

我正在使用Java 15, PostgreSQL和MyBatis为我的项目。

我只知道我的Client.java和ClinetMapper.java有问题，但不确定是什么原因导致这个错误。任何建议都会很有帮助的。

我的代码

Client.java

import java.util.UUID;
public class Client {
int id;
String clientNumber;
String name;
String email;
String healthCondition;

public Client(int id, String clientNumber, String name, String email, String healthCondition) {
this.id = id;
this.clientNumber = UUID.randomUUID().toString();
this.name = name;
this.email = email;
this.healthCondition = healthCondition;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getClientNumber() {
return clientNumber;
}
public void setClientNumber(String clientNumber) {
this.clientNumber = clientNumber;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getHealthCondition() {
return healthCondition;
}
public void setHealthCondition(String healthCondition) {
this.healthCondition = healthCondition;
}
}

ClientMapper.java

@Options(useGeneratedKeys=true, keyProperty="id") Client saveClient(Client client);

ClientMapper.xml (MyBatis文件)

<mapper namespace="nutri.api.infrastructure.datasource.client.ClientMapper">
<insert id="saveClient" parameterType="nutri.api.domain.model.Client">
INSERT INTO client.data (
id,
client_number,
name,
email,
health_condition
) VALUES (
nextval('client.client_id_seq'),
#{clientNumber},
#{name},
#{email},
#{healthCondition}
)
</insert>

Answer 1

对于插入语句，方法返回类型必须是void或int.
如果使用int，则返回插入的行数(在您的情况下总是1)。
生成的密钥将被设置为参数实例的id字段。
还应该指定keyColumn。

@Options(useGeneratedKeys=true, keyProperty="id", keyColumn="id")
int saveClient(Client client);

Client param = ... // prepare parameter
int count = clientMapper.saveClient(param);
// param.getId() will return the generated key