RunnerBuilder (JUnit API 文档)

java.lang.Object
- org.junit.runners.model.RunnerBuilder

```
public abstract class RunnerBuilder
extends Object
```
A RunnerBuilder is a strategy for constructing runners for classes. Only writers of custom runners should use RunnerBuilders. A custom runner class with a constructor taking a RunnerBuilder parameter will be passed the instance of RunnerBuilder used to build that runner itself. For example, imagine a custom runner that builds suites based on a list of classes in a text file:
```
 \@RunWith(TextFileSuite.class)
 \@SuiteSpecFile("mysuite.txt")
 class MySuite {}
 
```
The implementation of TextFileSuite might include:
```
 public TextFileSuite(Class testClass, RunnerBuilder builder) {
   // ...
   for (String className : readClassNames())
     addRunner(builder.runnerForClass(Class.forName(className)));
   // ...
 }
 
```
Since:
4.5
See Also:
Suite

Constructor Summary
Constructors
Constructor Description
RunnerBuilder()

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract Runner`	`runnerForClass(Class<?> testClass)`	Override to calculate the correct runner for a test class at runtime.
`List<Runner>`	`runners(Class<?> parent, Class<?>[] children)`	Constructs and returns a list of Runners, one for each child class in `children`.
`List<Runner>`	`runners(Class<?> parent, List<Class<?>> children)`
`Runner`	`safeRunnerForClass(Class<?> testClass)`	Always returns a runner, even if it is just one that prints an error instead of running tests.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - RunnerBuilder
```
public RunnerBuilder()
```
- Method Detail
  - runnerForClass
```
public abstract Runner runnerForClass(Class<?> testClass)
                               throws Throwable
```
    Override to calculate the correct runner for a test class at runtime.
    Parameters:
    testClass - class to be run
    Returns:
    a Runner
    Throws:
    Throwable - if a runner cannot be constructed
  - safeRunnerForClass
```
public Runner safeRunnerForClass(Class<?> testClass)
```
    Always returns a runner, even if it is just one that prints an error instead of running tests.
    Parameters:
    testClass - class to be run
    Returns:
    a Runner
  - runners
```
public List<Runner> runners(Class<?> parent,
                            Class<?>[] children)
                     throws InitializationError
```
    Constructs and returns a list of Runners, one for each child class in children. Care is taken to avoid infinite recursion: this builder will throw an exception if it is requested for another runner for parent before this call completes.
    Throws:
    InitializationError
  - runners
```
public List<Runner> runners(Class<?> parent,
                            List<Class<?>> children)
                     throws InitializationError
```
    Throws:
    InitializationError