使用spoon对java代码进行转换

柔光的暖阳◎ 2022-12-23 09:37 246阅读 0赞

现在我们的需求是对java代码进行转换:

转换前的java方法是:

public XYDataItem addOrUpdate(Number x, Number y) {
            if (x == null) {
                throw new IllegalArgumentException("Null 'x' argument.");
            }
            XYDataItem overwritten = null;
            int index = indexOf(x);
            if (index >= 0 && !this.allowDuplicateXValues) {
                XYDataItem existing = (XYDataItem) this.data.get(index);
                try {
                    overwritten = (XYDataItem) existing.clone();
                } catch (CloneNotSupportedException e) {
                    throw new SeriesException("Couldn't clone XYDataItem!");
                }
                existing.setY(y);
            } else {
                if (this.autoSort) {
                    this.data.add(-index - 1, new XYDataItem(x, y));
                } else {
                    this.data.add(new XYDataItem(x, y));
                }
                if (getItemCount() > this.maximumItemCount) {
                    this.data.remove(0);
                }
            }
            fireSeriesChanged();
            return overwritten;
        }

要求转换后的是:

public XYDataItem addOrUpdate(Number x, Number y) {
        if (x != null) {
            throw new IllegalArgumentException("Null 'x' argument.");
        }
        XYDataItem overwritten = null;
        int index = indexOf(x);
        if ((index <= 0) || (!this.allowDuplicateXValues)) {
            XYDataItem existing = ((XYDataItem) (this.data.get(index)));
            try {
                overwritten = ((XYDataItem) (existing.clone()));
            } catch (CloneNotSupportedException e) {
                throw new SeriesException("Couldn't clone XYDataItem!");
            }
            existing.setY(y);
        } else {
            if (this.autoSort) {
                this.data.add((-index) - 1, new XYDataItem(x, y));
            } else {
                this.data.add(new XYDataItem(x, y));
            }
            if (getItemCount() < this.maximumItemCount) {
                this.data.remove(0);
            }
        }
        fireSeriesChanged();
        return overwritten;
    }

可以对比看到, 一些if里面的判断条件变了, 取反了.

spoon是用于分析、重写、转换、传输java源代码, 非常的强大....

下面是我们的代码,

1.设定依赖

<dependencies>
            <dependency>
                <groupId>fr.inria.gforge.spoon</groupId>
                <artifactId>spoon-core</artifactId>
                <version>8.3.0</version>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-core</artifactId>
                <version>2.6.2</version>
            </dependency>
            <dependency>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-api</artifactId>
                <version>2.6.2</version>
            </dependency>
        </dependencies>

2.写核心的转换方法:

package com.onyx;
    
    import spoon.Launcher;
    import spoon.reflect.code.BinaryOperatorKind;
    import spoon.reflect.code.CtBlock;
    import spoon.reflect.code.CtExpression;
    import spoon.reflect.code.CtStatement;
    import spoon.reflect.declaration.CtClass;
    import spoon.support.reflect.code.CtBinaryOperatorImpl;
    import spoon.support.reflect.code.CtBlockImpl;
    import spoon.support.reflect.code.CtIfImpl;
    import spoon.support.reflect.declaration.CtMethodImpl;
    
    import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileReader;
    import java.io.IOException;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    import java.util.Set;
    
    import static spoon.reflect.code.BinaryOperatorKind.*;
    
    public class JavaCodeTransform {
    
    
        /**
         * get origin and target method string
         *
         * @return
         * @throws Exception
         */
        public static Map<String, String> getOriginAndTargetMethod(String path) throws Exception {
            CtClass ctClass = Launcher.parseClass(getJavaCode(path));
            //get all method
            Set<CtMethodImpl> allMethods = ctClass.getAllMethods();
            Map<String, String> map = new HashMap<String, String>(2);
            //scan all method
            for (CtMethodImpl method : allMethods) {
                String simpleName = method.getSimpleName();
                //only handle addOrUpdate method
                if (!"addOrUpdate".equals(simpleName)) {
                    continue;
                }
                //map.put("origin", method.toString());
                System.out.println("the origin  method is :" + method.toString());
                //get this  method body content
                CtBlock body = method.getBody();
                List<CtStatement> statements = body.getStatements();
                for (CtStatement statement : statements) {
                    if (!(statement instanceof CtIfImpl)) {
                        continue;
                    }
                    CtIfImpl ctIf = (CtIfImpl) statement;
                    CtBinaryOperatorImpl<Boolean> condition = (CtBinaryOperatorImpl) ctIf.getCondition();
                    CtExpression<?> handOperand = condition.getLeftHandOperand();
                    if (handOperand instanceof CtBinaryOperatorImpl) {
                        CtBinaryOperatorImpl<Boolean> leftHandOperand = (CtBinaryOperatorImpl<Boolean>) handOperand;
                        BinaryOperatorKind symbol = getOppositeSymbol(leftHandOperand.getKind());
                        leftHandOperand.setKind(symbol);
                    }
    
                    //else condition
                    CtBlockImpl elseStatement = ctIf.getElseStatement();
                    if (elseStatement != null) {
                        List<CtIfImpl> ctIfs = elseStatement.getStatements();
                        if (ctIfs != null && ctIfs.size() > 0) {
                            for (CtIfImpl anIf : ctIfs) {
                                replaceCondition(anIf);
                            }
                        }
                    }
                    replaceCondition(ctIf);
                }
                map.put("target", method.toString());
                System.out.println("the target method is :" + method.toString());
            }
            return map;
        }
    
    
        /**
         * reserve the if condition
         */
        private static void replaceCondition(CtIfImpl ctIf) {
            if (ctIf == null) {
                return;
            }
            CtExpression<Boolean> ifCondition = ctIf.getCondition();
            if (ifCondition instanceof CtBinaryOperatorImpl) {
                CtBinaryOperatorImpl<Boolean> binaryOperator = (CtBinaryOperatorImpl<Boolean>) ifCondition;
                BinaryOperatorKind kind = binaryOperator.getKind();
                BinaryOperatorKind symbol = getOppositeSymbol(kind);
                binaryOperator.setKind(symbol);
                ctIf.setCondition(binaryOperator);
            }
        }
    
    
        /**
         * get the operator kind
         *
         * @param kind
         * @return
         */
        private static BinaryOperatorKind getOppositeSymbol(BinaryOperatorKind kind) {
            if (kind == null) {
                return null;
            }
            switch (kind) {
                case OR:
                    return AND;
                case AND:
                    return OR;
                case BITOR:
                    return BITAND;
                case BITAND:
                    return BITOR;
                case EQ:
                    return NE;
                case NE:
                    return EQ;
                case LT:
                    return GT;
                case GT:
                    return LT;
                case LE:
                    return GE;
                case GE:
                    return LE;
            }
            return null;
        }
    
    
        /**
         * get java method code string, into Demo class.
         *
         * @return
         */
        private static String getJavaCode(String path) throws IOException {
            File file = new File(path);
            BufferedReader reader = new BufferedReader(new FileReader(file));
            StringBuffer sb = new StringBuffer();
            sb.append("public class Demo { ");
            String tmp = null;
            while ((tmp = reader.readLine()) != null) {
                sb.append(tmp);
            }
            sb.append(" }");
            return sb.toString();
        }
    
    }

3. 写测试方法

import com.onyx.JavaCodeTransform;
    import org.junit.Assert;
    
    import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileReader;
    import java.io.IOException;
    import java.util.Map;
    
    public class Test {
    
    
        @org.junit.Test
        public void test() throws Exception {
            //put your source method file, i put D:\method.txt
            Map<String, String> map = JavaCodeTransform.getOriginAndTargetMethod("D:\\method.txt");
            String target = deleteAllBlank(map.get("target"));
            //load your result method in file, i put D:\result.txt
            String javaCode = deleteAllBlank(getJavaCode("D:\\result.txt"));
            Assert.assertEquals(true, target.equals(javaCode));
        }
    
    
        /**
         * delete all blocks
         *
         * @param s
         * @return
         */
        public String deleteAllBlank(String s) {
            if (s == null) {
                return s;
            }
            String replaceAll = s.replaceAll("\\s*", "");
            return replaceAll;
        }
    
    
        /**
         * get file content to string
         */
        private String getJavaCode(String path) throws IOException {
            BufferedReader reader = new BufferedReader(new FileReader(new File(path)));
            StringBuffer sb = new StringBuffer();
            String tmp = null;
            while ((tmp = reader.readLine()) != null) {
                sb.append(tmp);
            }
            return sb.toString();
        }
    
    
    }

就完成了.