Non-static method 'updateBatchById(java.util.Collection<T>, int)' cannot be referenced from a static context
时间: 2024-01-09 10:20:38 浏览: 39
这个错误通常出现在Java中,它表示您正在尝试从静态上下文中引用非静态方法。这意味着您需要创建一个类的实例才能调用该方法,而不是直接从类本身调用该方法。您可以通过以下两种方法解决此问题:
1.创建类的实例并调用方法:
```java
YourClass obj = new YourClass();
obj.updateBatchById(collection, id);
```
2.将方法声明为静态方法:
```java
public static void updateBatchById(Collection<T> collection, int id) {
// your code here
}
```
相关问题
Non-static method 'selectCurstateById(java.util.Map)' cannot be referenced from a static context
This error message typically occurs when you try to invoke a non-static method from a static context. In Java, static methods and variables belong to the class itself, while non-static methods and variables belong to individual instances of the class.
To resolve this issue, you have a few options:
1. Create an object of the class that contains the `selectCurstateById` method and invoke the method using that object. For example:
```
MyClass obj = new MyClass();
obj.selectCurstateById(myMap);
```
2. Change the `selectCurstateById` method to be static if it doesn't rely on any instance-specific data. This way, you can call it directly from a static context. However, note that you won't be able to access non-static variables or methods within the `selectCurstateById` method.
```
public static void selectCurstateById(Map<String, Object> map) {
// method implementation
}
```
3. If the `selectCurstateById` method is intended to be an instance method and relies on instance-specific data, you need to reconsider the design of your code. You may need to rethink how you're calling the method or how you're structuring your classes.
Remember, without more context or code, it's difficult to provide a more specific solution.
Error:(32, 17) java: 对于invokeAll(ss), 找不到合适的方法 方法 java.util.concurrent.ExecutorService.<T>invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>>)不适用 (无法推断类型变量 T (参数不匹配; ss无法转换为java.util.Collection<? extends java.util.concurrent.Callable<T>>)) 方法 java.util.concurrent.ExecutorService.<T>invokeAll(java.util.Collection<? extends java.util.concurrent.Callable<T>>,long,java.util.concurrent.TimeUnit)不适用 (无法推断类型变量 T (实际参数列表和形式参数列表长度不同))
这个报错信息提示在第32行中的invokeAll方法调用参数不匹配,无法找到合适的方法。可能有两个问题:
1. ss类没有实现Callable接口,导致无法将其转换为Callable类型的集合,所以参数不匹配。
2. invokeAll方法需要传入一个Callable的集合,而你只传入了一个ss对象,和一个ss类型的集合也无法匹配,所以报错。
你可以将ss改为实现Callable接口,然后将其放入一个Callable类型的集合中,再将集合传入invokeAll方法中。代码示例如下:
```
public class test {
public static void main(String[] args) throws InterruptedException {
// 创建一个固定大小的线程池
ExecutorService service = Executors.newFixedThreadPool(3);
Callable<String> t1 = new ss();
List<Callable<String>> list = new ArrayList<>();
list.add(t1);
service.invokeAll(list);
// 关闭启动线程
service.shutdown();
// 等待子线程结束,再继续执行下面的代码
service.awaitTermination(Long.MAX_VALUE, TimeUnit.DAYS);
//System.out.println("all thread complete");
}
}
class ss implements Callable<String> {
@Override
public String call() {
System.out.println(Thread.currentThread().getName() + "执行call方法");
return null;
}
}
```
这样就可以避免参数不匹配的问题了。