我在代码中抛出了一堆自定义运行时异常，并且我想确保在所有公共方法中，我记录可能会（我自己）抛出哪个运行时异常以及原因。因为我要维护一个库，该库可供许多项目使用，并且我希望它对于抛出的（运行时）异常是预先的和可预测的，所以这将是非常高兴的。
是否有编译器选项，Maven插件，Intellij插件或自定义工具可以帮助我找到缺失的throws子句？随着检查的异常很容易，编译器将只是抱怨，如果我错过了一个，但是对于运行时异常都throws与@throws不执行。
我想到的一件事是暂时使我自己所有的运行时异常都经过检查的异常（它们已经共享了一个超类），但这将是一次性的练习。每次进行更改时，我都想验证我的代码/文档，因此我永远不会忘记记录我的运行时异常。
另一种方法是实际检查整个代码中的异常，然后仅在公共api中将它们转换为运行时：
class Foo {
// oops, throws not documented with @throws
public void publicMethod() {
try {
privateMethod1();
} catch (CheckedFooException e) {
throw new RuntimeFooException(e);
}
}
private void privateMethod1() throws CheckedFooException {
privateMethod2();
}
private void privateMethod2() throws CheckedFooException {
throw new CheckedFooException();
}
}
这种方法将迫使我在所有公共方法中考虑CheckedFooException。然后要检查是否错过了一个文档（即@throws RuntimeFooException），只需对它进行正则表达式搜索catch.*CheckedFooException并检查缺少的@throws条目。但是，这个过程相当繁琐（而且很多公共api都可以使用try ... catch语句）。
答：关于是否应该记录（您自己抛出的）运行时异常（到目前为止的总结：取决于情况），存在一些讨论，但是就我的问题的直接答案而言，已接受的答案可以充分回答它。我可以采取这种方法，实施我的用例，甚至花一些时间和精力来用它制作一个maven插件。我为此上传了一个清理启动项目。
在理解了你的问题并研究了这个主题之后，我终于找到了我认为是完成这项工作的最佳工具之一。有了这个，你不仅可以找到你没有记录的每个 throws 实例，而且你还可以找到你没有抛出任何东西但不小心记录了一个 throw 值的地方。
这背后的想法是将代码解析为抽象语法树。然后查找方法并查找方法中的 throws 语句。如果方法有任何 throw 语句，则从这些语句中提取异常名称。然后获取该方法的 Javadoc。检查所有 @throw 标记的 Javadoc 并获取记录的异常的名称。之后，比较异常抛出与记录的异常抛出。最后，你必须自己弄清楚，这取决于你的使用情况。
我为此使用的工具是 JavaParser。您可以在 Github 上的https://github.com/javaparser/javaparser上找到它们。我下载了他们的最新版本。他们的网站是https://javaparser.org/。他们写了一本关于这个主题的书，他们提到你可以为这本书支付 0 美元。但是，我没有读到，因为他们的程序也有 Javadoc 版本，可以在https://www.javadoc.io/doc/com.github.javaparser/javaparser-core/3.15.1找到。
我在下面写了一个演示代码。绝不意味着此代码是最终代码。这只是一个例子。您必须修复它以使其适用于您的案例。我没有考虑嵌套类、嵌套方法或方法内的类中的方法。此外，示例代码仅为类而不是接口编写。但是，很容易修改代码以更改为能够处理接口。
为此，您需要下载 javaParser，构建它，并在您的类路径中拥有它们的 javaparser-core-3.15.1.jar 或任何版本。
演示代码如下，test.java 是我编写的项目中的一个文件，但您可以使用任何文件。我还在示例代码中添加了注释。
import com.github.javaparser.*;
import com.github.javaparser.ast.CompilationUnit;
import com.github.javaparser.ast.comments.*;
import com.github.javaparser.ast.stmt.*;
import com.github.javaparser.ast.body.*;
import com.github.javaparser.javadoc.*;
import java.io.IOException;
import java.nio.file.*;
import java.nio.charset.Charset;
import java.util.*;
import java.util.stream.Collectors;
class Main{
public static void main(String[] args) throws IOException {
// Set file path
Path path = Paths.get("test.java");
// Set configuration
ParserConfiguration parseConfig = new ParserConfiguration();
parseConfig.setCharacterEncoding(Charset.forName("UTF-8"));
parseConfig.setTabSize(4);
parseConfig.setLanguageLevel(ParserConfiguration.LanguageLevel.JAVA_8);
// Get the parser
JavaParser jvParser = new JavaParser(parseConfig);
// Parse the result
ParseResult<CompilationUnit> parseResult = jvParser.parse(path);
// Check for problem
if ( !parseResult.isSuccessful() ) {
System.out.print("Parsing java code fail with the following problems:");
List<Problem> problems = parseResult.getProblems();
for ( Problem problem : problems ){
System.out.println(problem.getMessage());
}
return;
}
// Get the compilationUnit
// No optional checking for Optional<CompilationUnit> due to already check above.
CompilationUnit compilationUnit = parseResult.getResult().get();
// Get Classes
List<ClassOrInterfaceDeclaration> classes = compilationUnit.findAll(ClassOrInterfaceDeclaration.class).stream()
.filter(c -> !c.isInterface())
.collect(Collectors.toList());
// Traverse through each class to get method
for ( ClassOrInterfaceDeclaration c : classes ) {
// Get methods
List<MethodDeclaration> methods = c.getMethods();
for ( MethodDeclaration method : methods ) {
// Get the body statement
Optional <BlockStmt> body = method.getBody();
// if no body continue
if ( !body.isPresent() ) continue;
// After getting the body of the method code
// Search for the throw statements.
List<ThrowStmt> throwStatements = body.get().findAll(ThrowStmt.class);
// No throw statements, skip
if ( throwStatements.size() == 0 ) continue;
// Storing name of exceptions thrown into this list.
List<String> exceptionsThrown = new ArrayList<String>();
for ( ThrowStmt stmt : throwStatements ){
// Convert the throw expression to object creation expression and get the type.
String exceptionName = stmt.getExpression().asObjectCreationExpr().getType().toString();
if ( !exceptionsThrown.contains(exceptionName) ) exceptionsThrown.add(exceptionName);
}
/*
* Debug block for up to this point
System.out.println(method.getName());
System.out.println(exceptionsThrown);
System.out.println();
*
**/
// Get The Javadoc
Optional<Javadoc> javadoc = method.getJavadoc();
// To store the throws Tags
List<JavadocBlockTag> throwTags;
// A list of thrown exception that been documented.
List<String> exceptionsDocumented = new ArrayList<String>();
if ( javadoc.isPresent() ) {
throwTags = javadoc.get()
.getBlockTags()
.stream()
.filter(t -> t.getType() == JavadocBlockTag.Type.THROWS)
.collect(Collectors.toList());
for ( JavadocBlockTag tag : throwTags ) {
/*
* This may be buggy as
* the code assumed @throw exception
* to be on its own line. Therefore
* it will just take the first line as the exception name.
*/
String exceptionName = tag.getContent().toText()
.split("\n")[0]; // Use system line separator or change
// line accordingly.
if ( !exceptionsDocumented.contains(exceptionName) )
exceptionsDocumented.add(exceptionName);
}
}
// getBegin can extract the line out. But evaluating the optional would take some more code
// and is just for example so this was done like this without any checking.
System.out.println("Method: " + method.getName() + " at line " + method.getBegin());
System.out.println("Throws Exceptions: ");
System.out.println(exceptionsThrown);
System.out.println("Documented Exceptions:");
System.out.println(exceptionsDocumented);
System.out.println(System.lineSeparator() + System.lineSeparator());
}
}
}
}
test.java 内容：
package host.fai.lib.faiNumber;
/*
* Copyright 2019 Khang Hoang Nguyen
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
**/
/**
* <p>The <code>Base2Util</code> class is a final class that provides
* static methods for converting base 2 numbering system values in
* string representation to a Java's Primitive Data Type.
*
* <p>Currently this class supports converting base 2 numbers values
* in string representation to integer int values and integer
* long values.
*
* <p>This class can parse unsigned base 2 numbers to a supported
* integer signed type as if the integer type is unsigned. However,
* some of the values must be interprete properly to get the correct
* result.
*
* <p>Example for interpreting signed value as unsigned value.
*
* <p>It is possible to store the value of 18446744073709551615L
* into a long(signed) value. However, if that value is stored into a
* signed long integer type and if we were to interprete the value
* normally, we would get a -1L value. However, if the -1L value is
* pass to LongUtil.toStringAsUnsigned, we would get
* 18446744073709551615 in string format.
*
* <p>The following example is to get to -1L. First, we assign a value
* of 9223372036854775807L to an interger long variable, multiply that
* variable to 2L, and add 1L to it.
* <pre>
* long a = 9223372036854775807L * 2L + 1L;
* System.out.println(a);
* System.out.println(LongUtil.toStringAsUnsigned(a));
* </pre>
*
* <p>Example methods for interprete signed type as unsigned type
* in a decimal strings value are
* {@link IntUtil#toStringAsUnsigned(int) IntUtil.toStringAsUnsigned}
* and {@link LongUtil#toStringAsUnsigned(long) LongUtil.toStringAsUnsigned}.
* </p>
*
* @author Khang Hoang Nguyen
*
* @since 1.0.0.f
**/
public final class Base2Util{
private Base2Util(){};
/**
* Parse the input string as signed base 2 digits representation
* into an integer int value.
*
* @param input
* A string to be parsed as signed base 2 number to an
* integer int value.
*
* @return An integer int value of the signed base 2 number
* {@code input} string.
*
* @throws NumberFormatException
* If the {@code input} string contains invalid signed
* base 2 digits, if the {@code input} string contains a
* value that is smaller than the value of Integer.MIN_VALUE(
* {@value java.lang.Integer#MIN_VALUE}),
* or if the {@code input} string contains a value that
* is larger than the value of Integer.MAX_VALUE(
* {@value java.lang.Integer#MAX_VALUE}).
*
* @throws EmptyStringException
* If the {@code input} string is empty.
*
* @since 1.0.0.f
**/
public static final int toInt(final String input){
final int length = input.length();
if ( length == 0 ) throw new EmptyStringException();
final char ch1 = input.charAt(0); int start;
if ( ch1 == '-' || ch1 == '+' ){
if ( length == 1 ) throw new NumberFormatException(input);
start = 1;
} else {
start = 0;
}
int out = 0, c;
while ( start < length && input.charAt(start) == '0' ) start++;
final int runlen = length - start;
if ( runlen > 31 ){
if ( runlen > 32 ) throw new NumberFormatException(input);
if ( ch1 != '-' ) throw new NumberFormatException(input);
if ( input.charAt(start++) != '1') throw new NumberFormatException(input);
for ( ; start < length; start++){
if ( input.charAt(start) != '0' ) throw new NumberFormatException(input);
}
return -2147483648;
}
for ( ; start < length; start++){
c = (input.charAt(start) ^ '0');
if ( c > 1 ) throw new NumberFormatException(input);
out = (out << 1) | c;
}
if ( ch1 == '-' ) return ~out + 1;
return out;
}
/**
* Parse the input string as unsigned base 2 number representation
* into an integer int value as if the integer int is an unsigned
* type. For values that need to be interpreted correctly, see the
* {@link IntUtil#toStringAsUnsigned(int) toStringAsUnsigned} method
* of the {@link IntUtil IntUtil} class.
*
* @param input
* A string to be parsed as unsigned base 2 number to an
* integer int value as if the integer int is an unsigned
* type.
*
* @return An int value that represents an unsigned integer int
* value of the unsigned base 2 number {@code input} string.
*
* @throws NumberFormatException
* If the {@code input} string contains invalid unsigned
* base 2 digits, if the {@code input} string contains a
* value that is beyond the capacity of the integer int
* data type.
*
* @throws EmptyStringException
* If the {@code input} string is empty.
*
* @since 1.0.0.f
**/
public static final int toIntAsUnsigned(final String input){
final int length = input.length();
if ( length == 0 ) throw new EmptyStringException();
int start = 0;
int out = 0, c;
while ( start < length && input.charAt(start) == '0' ) start++;
if ( length - start > 32 ) throw new NumberFormatException(input);
for ( ; start < length; start++){
c = (input.charAt(start) ^ '0');
if ( c > 1 ) throw new NumberFormatException(input);
out = (out << 1) | c;
}
return out;
}
/**
* Parse the input string as signed base 2 number representation
* into an integer long value.
*
* @param input
* A string to be parsed as signed base 2 number to an
* integer long value.
*
* @return An integer long value of the signed base 2 number
* {@code input} string.
*
* @throws NumberFormatException
* If the {@code input} string contains invalid signed
* base 2 digits, if the {@code input} string contains a
* value that is smaller than the value of Long.MIN_VALUE(
* {@value java.lang.Long#MIN_VALUE}), or if
* the {@code input} string contains a value that is larger
* than the value of Long.MAX_VALUE(
* {@value java.lang.Long#MAX_VALUE}).
*
* @throws EmptyStringException
* If the {@code input} string is empty.
*
* @since 1.0.0.f
**/
public static final long toLong(final String input){
final int length = input.length();
if ( length == 0 ) throw new EmptyStringException();
final char ch1 = input.charAt(0); int start = 0;
if ( ch1 == '-' || ch1 == '+' ){
if ( length == 1 ) throw new NumberFormatException(input);
start = 1;
}
long out = 0, c;
while ( start < length && input.charAt(start) == '0' ) start++;
final int runlen = length - start;
if ( runlen > 63 ){
if ( runlen > 64 ) throw new NumberFormatException(input);
if ( ch1 != '-' ) throw new NumberFormatException(input);
if ( input.charAt(start++) != '1') throw new NumberFormatException(input);
for ( ; start < length; start++){
if ( input.charAt(start) != '0' ) throw new NumberFormatException(input);
}
return -9223372036854775808L;
}
for ( ; start < length; start++){
c = (input.charAt(start) ^ '0');
if ( c > 1L ) throw new NumberFormatException(input);
out = (out << 1) | c;
}
if ( ch1 == '-' ) return ~out + 1L;
return out;
}
/**
* Parse the input string as unsigned base 2 number representation
* into an integer long value as if the integer long is an unsigned
* type. For values that need to be interpreted correctly, see the
* {@link LongUtil#toStringAsUnsigned(long) toStringAsUnsigned} method
* of the {@link LongUtil LongUtil} class.
*
* @param input
* A string to be parsed as unsigned base 2 number to an
* integer long value as if the integer long is an unsigned
* type.
*
* @return An integer long value represent the unsigned integer
* long value of the unsigned base 2 number {@code input}
* string.
*
* @throws NumberFormatException
* If the {@code input} string contains invalid unsigned
* base 2 digits, or if the {code input} string
* contains a value that is beyond the capacity of the
* long data type.
*
* @throws EmptyStringException
* If the {@code input} string is empty.
*
* @since 1.0.0.f
**/
public static final long toLongAsUnsigned(final String input){
final int length = input.length();
if ( length == 0 ) throw new EmptyStringException();
int start = 0;
long out = 0, c;
while ( start < length && input.charAt(start) == '0' ) start++;
if ( length - start > 64 ) throw new NumberFormatException(input);
for ( ; start < length; start++){
c = (input.charAt(start) ^ '0');
if ( c > 1L ) throw new NumberFormatException(input);
out = (out << 1) | c;
}
return out;
}
}
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