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20 package com.puppycrawl.tools.checkstyle.checks.coding;
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22 import java.util.HashMap;
23 import java.util.Map;
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25 import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
26 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
27 import com.puppycrawl.tools.checkstyle.api.DetailAST;
28 import com.puppycrawl.tools.checkstyle.api.FullIdent;
29 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
30 import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
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55 @FileStatefulCheck
56 public class EqualsHashCodeCheck
57 extends AbstractCheck {
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66 public static final String MSG_KEY_HASHCODE = "equals.noHashCode";
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72 public static final String MSG_KEY_EQUALS = "equals.noEquals";
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75 private final Map<DetailAST, DetailAST> objBlockWithEquals = new HashMap<>();
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78 private final Map<DetailAST, DetailAST> objBlockWithHashCode = new HashMap<>();
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80 @Override
81 public int[] getDefaultTokens() {
82 return getRequiredTokens();
83 }
84
85 @Override
86 public int[] getAcceptableTokens() {
87 return getRequiredTokens();
88 }
89
90 @Override
91 public int[] getRequiredTokens() {
92 return new int[] {TokenTypes.METHOD_DEF};
93 }
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95 @Override
96 public void beginTree(DetailAST rootAST) {
97 objBlockWithEquals.clear();
98 objBlockWithHashCode.clear();
99 }
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101 @Override
102 public void visitToken(DetailAST ast) {
103 if (isEqualsMethod(ast)) {
104 objBlockWithEquals.put(ast.getParent(), ast);
105 }
106 else if (isHashCodeMethod(ast)) {
107 objBlockWithHashCode.put(ast.getParent(), ast);
108 }
109 }
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117 private static boolean isEqualsMethod(DetailAST ast) {
118 final DetailAST modifiers = ast.getFirstChild();
119 final DetailAST parameters = ast.findFirstToken(TokenTypes.PARAMETERS);
120
121 return CheckUtil.isEqualsMethod(ast)
122 && modifiers.findFirstToken(TokenTypes.LITERAL_PUBLIC) != null
123 && isObjectParam(parameters.getFirstChild())
124 && (ast.findFirstToken(TokenTypes.SLIST) != null
125 || modifiers.findFirstToken(TokenTypes.LITERAL_NATIVE) != null);
126 }
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134 private static boolean isHashCodeMethod(DetailAST ast) {
135 final DetailAST modifiers = ast.getFirstChild();
136 final DetailAST type = ast.findFirstToken(TokenTypes.TYPE);
137 final DetailAST methodName = ast.findFirstToken(TokenTypes.IDENT);
138 final DetailAST parameters = ast.findFirstToken(TokenTypes.PARAMETERS);
139
140 return type.getFirstChild().getType() == TokenTypes.LITERAL_INT
141 && "hashCode".equals(methodName.getText())
142 && modifiers.findFirstToken(TokenTypes.LITERAL_PUBLIC) != null
143 && modifiers.findFirstToken(TokenTypes.LITERAL_STATIC) == null
144 && parameters.getFirstChild() == null
145 && (ast.findFirstToken(TokenTypes.SLIST) != null
146 || modifiers.findFirstToken(TokenTypes.LITERAL_NATIVE) != null);
147 }
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154 private static boolean isObjectParam(DetailAST paramNode) {
155 final DetailAST typeNode = paramNode.findFirstToken(TokenTypes.TYPE);
156 final FullIdent fullIdent = FullIdent.createFullIdentBelow(typeNode);
157 final String name = fullIdent.getText();
158 return "Object".equals(name) || "java.lang.Object".equals(name);
159 }
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161 @Override
162 public void finishTree(DetailAST rootAST) {
163 objBlockWithEquals
164 .entrySet().stream().filter(detailASTDetailASTEntry -> {
165 return objBlockWithHashCode.remove(detailASTDetailASTEntry.getKey()) == null;
166 }).forEach(detailASTDetailASTEntry -> {
167 final DetailAST equalsAST = detailASTDetailASTEntry.getValue();
168 log(equalsAST, MSG_KEY_HASHCODE);
169 });
170 objBlockWithHashCode.forEach((key, equalsAST) -> {
171 log(equalsAST, MSG_KEY_EQUALS);
172 });
173 }
174
175 }