JsonToStringStyler for model classes used in the utPLSQL project

Author: PhilippSalvisberg

sqldev/src/main/java/org/utplsql/sqldev/model/JsonToStringStyler.java

@@ -15,30 +15,149 @@
  */
 package org.utplsql.sqldev.model;
 
-import org.springframework.core.style.DefaultToStringStyler;
+import java.util.List;
+import java.util.Map;
+import java.util.StringJoiner;
+
+import javax.annotation.Nullable;
+
 import org.springframework.core.style.ToStringStyler;
-import org.springframework.util.ClassUtils;
+import org.springframework.core.style.ValueStyler;
 
-public class UtplsqlToStringStyler extends DefaultToStringStyler {
-    public static final ToStringStyler INSTANCE = new UtplsqlToStringStyler();
+public class JsonToStringStyler implements ToStringStyler, ValueStyler{
+    public static final ToStringStyler INSTANCE = new JsonToStringStyler();
+    public static final String INDENT_SPACES = "    ";
+    private int indent = 0;
+    
+    private void newLine(StringBuilder buffer) {
+        buffer.append('\n');
+        buffer.append(getIndentSpaces(0));
+    }
+    
+    private String getIndentSpaces(int indentOffset) {
+        StringBuilder sb = new StringBuilder();
+        for (int i=0; i<indent+indentOffset; i++) {
+            sb.append(INDENT_SPACES);
+        }
+        return sb.toString();
+    }
 
-    public UtplsqlToStringStyler() {
-        super(new UtplsqlValueStyler());
+    private String getStringStyle(String value) {
+        StringBuilder sb = new StringBuilder();
+        sb.append('"');
+        sb.append(value.replace("\"", "\\\"").replace("\n", "\\n").replace("\r", ""));
+        sb.append('"');
+        return sb.toString();
     }
 
-    @Override
-    public void styleFieldSeparator(StringBuilder buffer) {
-        buffer.append(",\n");
+    private String getArrayStyle(Object[] array) {
+        if (array.length == 0) {
+            return "[]";
+        }
+
+        StringJoiner result = new StringJoiner(",\n" + getIndentSpaces(1), "[\n" + getIndentSpaces(1) , "\n" + getIndentSpaces(0) + "]");
+        indent++;
+        for (Object o : array) {
+            result.add(style(o));
+        }
+        indent--;
+        return result.toString();
     }
 
+    private String getListStyle(List<?> list) {
+        if (list.isEmpty()) {
+            return "[]";
+        }
+        
+        StringJoiner result = new StringJoiner(",\n" + getIndentSpaces(1), "[\n" + getIndentSpaces(1) , "\n" + getIndentSpaces(0) + "]");
+        indent++;
+        for (Object o : list) {
+            result.add(style(o));
+        }
+        indent--;
+        return result.toString();
+    }    
+    
+    private String getMapStyle(Map<?, ?> map) {
+        if (map.isEmpty()) {
+            return "[]";
+        }
+        
+        StringJoiner result = new StringJoiner(",\n" + getIndentSpaces(1), "[\n" + getIndentSpaces(1) , "\n" + getIndentSpaces(0) + "]");
+        indent++;
+        for (Object o : map.values()) {
+            result.add(style(o));
+        }
+        indent--;
+        return result.toString();
+    }    
+    
+    private String getDefaultStyle(Object value) {
+        return String.valueOf(value);
+    }
+    
     @Override
     public void styleStart(StringBuilder buffer, Object obj) {
+        indent++;
         if (!obj.getClass().isArray()) {
-            buffer.append("[").append(ClassUtils.getShortName(obj.getClass()));
-            buffer.append('\n');
+            buffer.append("{");
+            newLine(buffer);
+            buffer.append("\"className\": ");
+            buffer.append('"');
+            buffer.append(obj.getClass().getSimpleName());
+            buffer.append('"');
+            buffer.append(',');
         } else {
             buffer.append('[');
             styleValue(buffer, obj);
         }
     }
+    
+    @Override
+    public void styleEnd(StringBuilder buffer, Object obj) {
+        indent--;
+        newLine(buffer);
+        if (!obj.getClass().isArray()) {
+            buffer.append('}');
+        } else {
+            buffer.append(']');
+        }
+    }
+
+    @Override
+    public void styleField(StringBuilder buffer, String fieldName, @Nullable Object value) {
+        newLine(buffer);
+        buffer.append('"');
+        buffer.append(fieldName);
+        buffer.append('"');
+        buffer.append(": ");
+        styleValue(buffer, value);
+    }
+
+    @Override
+    public void styleValue(StringBuilder buffer, Object value) {
+        buffer.append(style(value));
+    }
+    
+    @Override
+    public void styleFieldSeparator(StringBuilder buffer) {
+        buffer.append(",");
+    }
+
+    @Override
+    public String style(Object value) {
+        if (value == null) {
+            return "null";
+        } else if (value instanceof String) {
+            return getStringStyle((String) value);
+        } else if (value instanceof Object[]) {
+            return getArrayStyle((Object[]) value);
+        } else if (value instanceof List<?>) {
+            return getListStyle((List<?>) value);
+        } else if (value instanceof Map) {
+            return getMapStyle((Map<?, ?>) value);
+        } else {
+            return getDefaultStyle(value);
+        }
+    }
 }