support writing values

json-path/src/main/java/com/jayway/jsonpath/JsonPath.java

@@ -17,7 +17,8 @@ package com.jayway.jsonpath;
 
 import com.jayway.jsonpath.internal.JsonReader;
 import com.jayway.jsonpath.internal.Utils;
-import com.jayway.jsonpath.internal.spi.compiler.PathCompiler;
+import com.jayway.jsonpath.internal.spi.compiler.*;
+import com.jayway.jsonpath.spi.compiler.EvaluationContext;
 import com.jayway.jsonpath.spi.compiler.Path;
 import com.jayway.jsonpath.spi.http.HttpProviderFactory;
 import com.jayway.jsonpath.spi.json.JsonProvider;
@@ -28,6 +29,8 @@ import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
+import java.util.List;
+import java.util.Map;
 
 import static com.jayway.jsonpath.internal.Utils.*;
 
@@ -203,6 +206,63 @@ public class JsonPath {
     }
 
 
+    /**
+     * Writes the provided value at this path to the provided json document.
+     * Note that the document must be identified as either a List or Map by
+     * the {@link JsonProvider}
+     *
+     * @param jsonObject    a container Object
+     * @param value         value to set
+     * @param configuration configuration to use
+     * @return a modified container object
+     */
+    public Map write(Object jsonObject, Object value, Configuration configuration) {
+
+        // new configuration that will always return list
+        Configuration.ConfigurationBuilder builder = new Configuration.ConfigurationBuilder();
+        Configuration readConfig = builder
+                .jsonProvider(configuration.getProvider())
+                .options(Option.ALWAYS_RETURN_LIST)
+                .build();
+
+        // clone the path for manipulation to prevent modifications by reference
+        Path clonedPath = path.clone();
+        RootPathToken clonedRoot = clonedPath.getRoot();
+        PathToken tail = clonedRoot.getTail();
+        PathToken parent = tail.getPrevious();
+        parent.setNext(null);
+
+        // get results for parent paths
+        EvaluationContext res = clonedPath.evaluate(jsonObject, readConfig);
+
+        for (Object valueResult : (List<Object>) res.getValueResult()) {
+            Class clazz = valueResult.getClass();
+            // set index value in array
+            if (List.class.isAssignableFrom(clazz)) {
+
+                ArrayPathToken arrayPathToken = (ArrayPathToken) tail;
+                List<Integer> criteria = arrayPathToken.getCriteria();
+                Integer index = criteria.get(0);
+
+                List list = (List) valueResult;
+                list.set(index, value);
+            }
+            // set property value on object
+            else if (Map.class.isAssignableFrom(clazz)) {
+
+                PropertyPathToken propertyPathToken = (PropertyPathToken) tail;
+                List<String> properties = propertyPathToken.getProperties();
+                String key = properties.get(0);
+
+                Map map = (Map) valueResult;
+                map.put(key, value);
+            }
+        }
+
+        return (Map) jsonObject;
+    }
+
+
     /**
      * Applies this JsonPath to the provided json string
      *
@@ -215,6 +275,18 @@ public class JsonPath {
         return read(json, Configuration.defaultConfiguration());
     }
 
+    /**
+     * Writes the provided value at this path to the provided json string.
+     *
+     * @param json a json string
+     * @param value value to set at path
+     * @return a modified container object
+     */
+    public Map write(String json, Object value) {
+        Configuration configuration = Configuration.defaultConfiguration();
+        return write(json, value, configuration);
+    }
+
     /**
      * Applies this JsonPath to the provided json string
      *
@@ -231,6 +303,18 @@ public class JsonPath {
         return read(configuration.getProvider().parse(json), configuration);
     }
 
+    /**
+     *
+     * @param json a json string
+     * @param value value to set at path
+     * @param configuration
+     * @return a modified container object
+     */
+    public Map write(String json, Object value, Configuration configuration) {
+        Object jsonObject = configuration.getProvider().parse(json);
+        return write(jsonObject, value, configuration);
+    }
+
     /**
      * Applies this JsonPath to the provided json URL
      *

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/ArrayPathToken.java

@@ -13,7 +13,7 @@ import static java.lang.String.format;
 /**
  *
  */
-class ArrayPathToken extends PathToken {
+public class ArrayPathToken extends PathToken {
 
     private static final Logger logger = LoggerFactory.getLogger(ArrayPathToken.class);
 
@@ -36,6 +36,10 @@ class ArrayPathToken extends PathToken {
         this.isDefinite = (Operation.SINGLE_INDEX == operation || Operation.CONTEXT_SIZE == operation);
     }
 
+    public List<Integer> getCriteria() {
+        return criteria;
+    }
+
     @Override
     void evaluate(String currentPath, Object model, EvaluationContextImpl ctx) {
         if(model == null){
@@ -167,4 +171,12 @@ class ArrayPathToken extends PathToken {
     boolean isTokenDefinite() {
         return isDefinite;
     }
+
+    @Override
+    public ArrayPathToken clone() {
+        ArrayPathToken pathToken = new ArrayPathToken(criteria, operation);
+        cloneTo(pathToken);
+        return pathToken;
+    }
+
 }

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/CompiledPath.java

@@ -6,14 +6,17 @@ import com.jayway.jsonpath.spi.compiler.Path;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-class CompiledPath implements Path {
+public class CompiledPath implements Path {
 
     private static final Logger logger = LoggerFactory.getLogger(CompiledPath.class);
 
-    private final PathToken root;
+    private final RootPathToken root;
 
+    public RootPathToken getRoot() {
+        return root;
+    }
 
-    public CompiledPath(PathToken root) {
+    public CompiledPath(RootPathToken root) {
         this.root = root;
     }
 
@@ -34,6 +37,16 @@ class CompiledPath implements Path {
         return root.isPathDefinite();
     }
 
+    @Override
+    public Path clone() {
+        RootPathToken newRoot = null;
+        if (root != null) {
+            newRoot = root.clone();
+        }
+        Path path = new CompiledPath(newRoot);
+        return path;
+    }
+
     @Override
     public String toString() {
         return root.toString();

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/EvaluationContextImpl.java

@@ -49,6 +49,15 @@ class EvaluationContextImpl implements EvaluationContext {
         return configuration;
     }
 
+    @Override
+    public Object getValueResult() {
+        return valueResult;
+    }
+
+    @Override
+    public Object getPathResult() {
+        return pathResult;
+    }
 
     @Override
     public <T> T getValue() {

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/FilterPathToken.java

@@ -70,4 +70,12 @@ class FilterPathToken extends PathToken {
     boolean isTokenDefinite() {
         return false;
     }
+
+    @Override
+    public FilterPathToken clone() {
+        FilterPathToken pathToken = new FilterPathToken(filters);
+        cloneTo(pathToken);
+        return pathToken;
+    }
+
 }

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/PathCompiler.java

@@ -50,7 +50,11 @@ public class PathCompiler {
         }
 
         RootPathToken root = null;
-
+        PathToken pathToken = null;
+        /**
+         * Track previous path token we looped through, for setting previous links.
+         */
+        PathToken previousPathToken = null;
 
         char[] chars = path.toCharArray();
         int i = 0;
@@ -104,12 +108,20 @@ public class PathCompiler {
                     i += positions;
                     break;
             }
+
+            pathToken = PathComponentAnalyzer.analyze(fragment, filterList);
+
+            // set the previous link
+            pathToken.setPrevious(previousPathToken);
+
             if (root == null) {
-                root = (RootPathToken) PathComponentAnalyzer.analyze(fragment, filterList);
+                root = (RootPathToken) pathToken;
             } else {
-                root.append(PathComponentAnalyzer.analyze(fragment, filterList));
+                root.append(pathToken);
             }
 
+            previousPathToken = pathToken;
+
         } while (i < chars.length);
 
         Path pa = new CompiledPath(root);

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/PathToken.java

@@ -8,11 +8,28 @@ import com.jayway.jsonpath.spi.json.JsonProvider;
 
 import java.util.List;
 
-abstract class PathToken {
+public abstract class PathToken {
 
+    private PathToken previous;
     private PathToken next;
     private Boolean definite = null;
 
+    public PathToken getPrevious() {
+        return previous;
+    }
+
+    public void setPrevious(PathToken previous) {
+        this.previous = previous;
+    }
+
+    public void setNext(PathToken next) {
+        this.next = next;
+    }
+
+    public void setDefinte(Boolean definite) {
+        this.definite = definite;
+    }
+
     PathToken appendTailToken(PathToken next) {
         this.next = next;
         return next;
@@ -94,14 +111,14 @@ abstract class PathToken {
     }
 
 
-    PathToken next() {
+    public PathToken next() {
         if (isLeaf()) {
             throw new IllegalStateException("Current path token is a leaf");
         }
         return next;
     }
 
-    boolean isLeaf() {
+    public boolean isLeaf() {
         return next == null;
     }
 
@@ -154,4 +171,27 @@ abstract class PathToken {
 
     abstract String getPathFragment();
 
+    @Override
+    abstract public PathToken clone();
+
+    /**
+     * Deep clone this path's fields to the provided path.
+     * While next links are cloned, previous links are only updated, to prevent infinite recursion.
+     * Cannot use standard clone and super calls for sub-classes due to abstract modifier.
+     *
+     * @param pathToken
+     */
+    public void cloneTo(PathToken pathToken) {
+        PathToken newNext;
+        if (next != null) {
+            newNext = next.clone();
+            newNext.setPrevious(pathToken);
+        }
+        else {
+            newNext = null;
+        }
+        pathToken.setNext(newNext);
+        pathToken.setDefinte(definite);
+    }
+
 }

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/PropertyPathToken.java

@@ -8,7 +8,7 @@ import java.util.List;
 /**
  *
  */
-class PropertyPathToken extends PathToken {
+public class PropertyPathToken extends PathToken {
 
     private final List<String> properties;
 
@@ -41,4 +41,12 @@ class PropertyPathToken extends PathToken {
                 .append(Utils.join(", ", "'", properties))
                 .append("]").toString();
     }
+
+    @Override
+    public PropertyPathToken clone() {
+        PropertyPathToken pathToken = new PropertyPathToken(properties);
+        cloneTo(pathToken);
+        return pathToken;
+    }
+
 }

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/RootPathToken.java

@@ -6,7 +6,7 @@ import org.slf4j.LoggerFactory;
 /**
  *
  */
-class RootPathToken extends PathToken /*implements Path*/ {
+public class RootPathToken extends PathToken /*implements Path*/ {
 
     private static final Logger logger = LoggerFactory.getLogger(RootPathToken.class);
 
@@ -18,11 +18,23 @@ class RootPathToken extends PathToken /*implements Path*/ {
         this.tokenCount = 1;
     }
 
+    public PathToken getTail() {
+        return tail;
+    }
+
+    public void setTail(PathToken tail) {
+        this.tail = tail;
+    }
+
     @Override
     public int getTokenCount() {
         return tokenCount;
     }
 
+    public void setTokenCount(int tokenCount) {
+        this.tokenCount = tokenCount;
+    }
+
     public RootPathToken append(PathToken next) {
         this.tail = tail.appendTailToken(next);
         this.tokenCount++;
@@ -63,4 +75,25 @@ class RootPathToken extends PathToken /*implements Path*/ {
     boolean isTokenDefinite() {
         return true;
     }
+
+    public PathToken walkToTail() {
+        PathToken next = this;
+        while (next != null && ! next.isLeaf()) {
+            next = next.next();
+        }
+        return next;
+    }
+
+    @Override
+    public RootPathToken clone() {
+        RootPathToken pathToken = new RootPathToken();
+        // deep clone 'next' path
+        cloneTo(pathToken);
+        // get new tail clone
+        PathToken tail = pathToken.walkToTail();
+        pathToken.setTail(tail);
+        pathToken.setTokenCount(tokenCount);
+        return pathToken;
+    }
+
 }

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/ScanPathToken.java

@@ -171,4 +171,12 @@ class ScanPathToken extends PathToken {
 
         boolean matches(Object model);
     }
+
+    @Override
+    public ScanPathToken clone() {
+        ScanPathToken pathToken = new ScanPathToken();
+        cloneTo(pathToken);
+        return pathToken;
+    }
+
 }

json-path/src/main/java/com/jayway/jsonpath/internal/spi/compiler/WildcardPathToken.java

@@ -30,4 +30,12 @@ class WildcardPathToken extends PathToken {
     public String getPathFragment() {
         return "[*]";
     }
+
+    @Override
+    public ScanPathToken clone() {
+        ScanPathToken pathToken = new ScanPathToken();
+        cloneTo(pathToken);
+        return pathToken;
+    }
+
 }

json-path/src/main/java/com/jayway/jsonpath/spi/compiler/EvaluationContext.java

@@ -12,6 +12,10 @@ public interface EvaluationContext {
      */
     Configuration configuration();
 
+    Object getValueResult();
+
+    Object getPathResult();
+
     /**
      * This method does not adhere to configuration settings. It will return a single object (not wrapped in a List) even if the
      * configuration contains the {@link com.jayway.jsonpath.Option#ALWAYS_RETURN_LIST}

json-path/src/main/java/com/jayway/jsonpath/spi/compiler/Path.java

@@ -1,6 +1,7 @@
 package com.jayway.jsonpath.spi.compiler;
 
 import com.jayway.jsonpath.Configuration;
+import com.jayway.jsonpath.internal.spi.compiler.RootPathToken;
 
 /**
  *
@@ -9,6 +10,10 @@ public interface Path {
 
     EvaluationContext evaluate(Object model, Configuration configuration);
 
+    public RootPathToken getRoot();
+
     boolean isDefinite();
 
+    public Path clone();
+
 }

json-path/src/test/java/com/jayway/jsonpath/JsonPathTest.java

@@ -1,11 +1,13 @@
 package com.jayway.jsonpath;
 
 import com.jayway.jsonpath.internal.spi.compiler.PathCompiler;
+import com.jayway.jsonpath.spi.json.JsonProvider;
 import com.jayway.jsonpath.spi.json.JsonProviderFactory;
 import com.jayway.jsonpath.util.ScriptEngineJsonPath;
 import org.assertj.core.api.Assertions;
 import org.junit.Test;
 
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -192,6 +194,70 @@ public class JsonPathTest {
         assertEquals(2, result.values().size());
     }
 
+    @Test
+    public void write_store_book_author() throws Exception {
+
+        JsonPath path = JsonPath.compile("$.store.book[0].author");
+
+        String writeAuthor = "Douglas Adams";
+        Map jsonMap = path.write(DOCUMENT, writeAuthor);
+
+        JsonProvider provider = JsonProviderFactory.createProvider();
+        String json = provider.toJson(jsonMap);
+        String readAuthor = path.read(json);
+        assertEquals(writeAuthor, readAuthor);
+    }
+
+    @Test
+    public void write_store_book_authors() throws Exception {
+
+        JsonPath path = JsonPath.compile("$.store.book[0,1].author");
+
+        String writeAuthor = "Douglas Adams";
+        Map jsonMap = path.write(DOCUMENT, writeAuthor);
+
+        JsonProvider provider = JsonProviderFactory.createProvider();
+        String json = provider.toJson(jsonMap);
+        List<String> readAuthors = path.read(json);
+
+        for (String readAuthor : readAuthors) {
+            assertEquals(writeAuthor, readAuthor);
+        }
+    }
+
+    @Test
+    public void write_store_book_0_shallow() throws Exception {
+
+        JsonPath path = JsonPath.compile("$.store.book[0]");
+
+        String writeBook = "Book";
+        Map jsonMap = path.write(DOCUMENT, writeBook);
+
+        JsonProvider provider = JsonProviderFactory.createProvider();
+        String json = provider.toJson(jsonMap);
+        String readBook = path.read(json);
+
+        assertEquals(writeBook, readBook);
+    }
+
+    @Test
+    public void write_store_book_0_deep() throws Exception {
+
+        JsonPath path = JsonPath.compile("$.store.book[0]");
+
+        HashMap<String, Object> writeBook = new HashMap<String, Object>();
+        String writeBookAuthor = "New Author";
+        writeBook.put("author", writeBookAuthor);
+        Map jsonMap = path.write(DOCUMENT, writeBook);
+
+        JsonProvider provider = JsonProviderFactory.createProvider();
+        String json = provider.toJson(jsonMap);
+        JsonPath readPath = JsonPath.compile("$.store.book[0].author");
+        String readBookAuthor = readPath.read(json);
+
+        assertEquals(writeBookAuthor, readBookAuthor);
+    }
+
     @Test
     public void read_store_book_1() throws Exception {