SpringBoot FailureAnalyzer实例使用教程

package org.springframework.boot.diagnostics;
/**
 * 该接口用户分析异常堆栈信息，将其转换为用户可读的对象信息，通常情况下，对象包含错误描述和建议.
 * @since 1.4.0
 */
@FunctionalInterface
public interface FailureAnalyzer {
	/**
	 * 返回异常错误的分析对象，或null
	 * @param failure the failure
	 * @return the analysis or {@code null}
	 */
	FailureAnalysis analyze(Throwable failure);
}

package org.springframework.boot.diagnostics;
/**
 * The result of analyzing a failure.
 *
 * @author Andy Wilkinson
 * @since 1.4.0
 */
public class FailureAnalysis {
  // 问题描述
	private final String description;
  // 动作(解决问题的方法)
	private final String action;
  // 问题原因
	private final Throwable cause;
	public FailureAnalysis(String description, String action, Throwable cause) {
		this.description = description;
		this.action = action;
		this.cause = cause;
	}
  // get 方法...
}

package org.springframework.boot.diagnostics.analyzer;
import org.springframework.boot.diagnostics.AbstractFailureAnalyzer;
import org.springframework.boot.diagnostics.FailureAnalysis;
import org.springframework.boot.web.server.PortInUseException;
class PortInUseFailureAnalyzer extends AbstractFailureAnalyzer<PortInUseException> {
	@Override
	protected FailureAnalysis analyze(Throwable rootFailure, PortInUseException cause) {
		return new FailureAnalysis("Web server failed to start. Port " + cause.getPort() + " was already in use.",
				"Identify and stop the process that's listening on port " + cause.getPort() + " or configure this "
						+ "application to listen on another port.",
				cause);
	}
}

public abstract class AbstractFailureAnalyzer<T extends Throwable> implements FailureAnalyzer {
	@Override
	public FailureAnalysis analyze(Throwable failure) {
		T cause = findCause(failure, getCauseType());
		return (cause != null) ? analyze(failure, cause) : null;
	}
	/**
	 * 重新定义钩子方法，将参数与泛型对象关联，具象化了每一个子类需要实现的功能
	 */
	protected abstract FailureAnalysis analyze(Throwable rootFailure, T cause);
	@SuppressWarnings("unchecked")
	protected Class<? extends T> getCauseType() {
		return (Class<? extends T>) ResolvableType.forClass(AbstractFailureAnalyzer.class, getClass()).resolveGeneric();
	}
	@SuppressWarnings("unchecked")
	protected final <E extends Throwable> E findCause(Throwable failure, Class<E> type) {
		while (failure != null) {
			if (type.isInstance(failure)) {
				return (E) failure;
			}
			failure = failure.getCause();
		}
		return null;
	}
}

//PortInUseFailureAnalyzer 负责解析 PortInUseException 异常
class PortInUseFailureAnalyzer extends AbstractFailureAnalyzer<PortInUseException>{
  ...
}

package com.andy.spring.boot.docker.exception;
public class CustomApplicationException extends RuntimeException {
    public CustomApplicationException(String msg){
        super(msg);
    }
}

package com.andy.spring.boot.docker.analyzer;
import com.andy.spring.boot.docker.exception.CustomApplicationException;
import org.springframework.boot.diagnostics.AbstractFailureAnalyzer;
import org.springframework.boot.diagnostics.FailureAnalysis;
public class CustomApplicationFailureAnalyzer extends AbstractFailureAnalyzer<CustomApplicationException> {
    @Override
    protected FailureAnalysis analyze(Throwable rootFailure, CustomApplicationException cause) {
        return new FailureAnalysis("Yeah, 自定义失败分析器出现了...!",
                "Ummm... 啥都不做，删库跑路",
                cause);
    }
}

package com.andy.spring.boot.docker.service;
import com.andy.spring.boot.docker.exception.CustomApplicationException;
import org.springframework.stereotype.Component;
@Component
public class CacheService {
    public CacheService() {
        throw new CustomApplicationException("bean 初始化异常");
    }
}