#4 Refactor Constant Pool item descriptor

FormatCLASS/src/main/java/org/freeinternals/format/classfile/ClassFile.java

@@ -482,15 +482,21 @@ public byte[] getClassByteArray(final int startIndex, final int length) {
     public String getCPDescription(final int index) {
         // Invalid index
         if (index >= this.constant_pool_count.value) {
-            return null;
+            throw new IllegalArgumentException(String.format("Index is bigger than constant pool size. size=%d, index=%d", this.constant_pool_count.value, index));
         }
 
         // Special index: empty
         if (index == 0) {
-            return null;
+            throw new IllegalArgumentException("Constant Pool Index cannot be zero. index=" + index);
+        }
+
+        CPInfo cp = this.constant_pool[index];
+        if (cp == null) {
+            // For Double, Long type, each item take two indexs, so there could be some index contains nothing.
+            throw new IllegalArgumentException("Nothing exist at the Constant Pool Index. index=" + index);
         }
 
-        return new CPDescr().getCPDescr(index);
+        return cp.toString(this.constant_pool) + ", " + cp.getName();
     }
 
     /**
@@ -509,185 +515,6 @@ public String toString() {
                 + this.methods_count.value.value + " method(s)";
     }
 
-    ///////////////////////////////////////////////////////////////////////////
-    // Get extracted data
-    ///////////////////////////////////////////////////////////////////////////
-    // Internal Classes
-    private static enum Descr_NameAndType {
-
-        RAW(1), FIELD(2), METHOD(3);
-        private final int enum_value;
-
-        Descr_NameAndType(final int value) {
-            this.enum_value = value;
-        }
-
-        public int value() {
-            return this.enum_value;
-        }
-    }
-
-    // TODO - Refactor this method into each Constant type
-    private class CPDescr {
-
-        public String getCPDescr(final int index) {
-            final StringBuilder sb = new StringBuilder(40);
-
-            if (index >= 0 && index < ClassFile.this.constant_pool.length) {
-                CPInfo cp_info = ClassFile.this.constant_pool[index];
-                if (cp_info != null) {
-                    sb.append(cp_info.getName()).append(": ");
-                    if (cp_info instanceof ConstantUtf8Info) {
-                        sb.append(this.getDescr_Utf8((ConstantUtf8Info) cp_info));
-                    } else if (cp_info instanceof ConstantIntegerInfo) {
-                        sb.append(String.valueOf(((ConstantIntegerInfo) cp_info).integerValue));
-                    } else if (cp_info instanceof ConstantFloatInfo) {
-                        sb.append(String.valueOf(((ConstantFloatInfo) cp_info).floatValue));
-                    } else if (cp_info instanceof ConstantLongInfo) {
-                        sb.append(String.valueOf(((ConstantLongInfo) cp_info).longValue));
-                    } else if (cp_info instanceof ConstantDoubleInfo) {
-                        sb.append(String.valueOf(((ConstantDoubleInfo) cp_info).doubleValue));
-                    } else if (cp_info instanceof ConstantClassInfo) {
-                        sb.append(this.getDescr_Class((ConstantClassInfo) cp_info));
-                    } else if (cp_info instanceof ConstantStringInfo) {
-                        // done here
-                        sb.append(this.getDescr_String((ConstantStringInfo) cp_info));
-                    } else if (cp_info instanceof ConstantFieldrefInfo) {
-                        sb.append(this.getDescr_Fieldref((ConstantFieldrefInfo) cp_info));
-                    } else if (cp_info instanceof ConstantMethodrefInfo) {
-                        sb.append(this.getDescr_Methodref((ConstantMethodrefInfo) cp_info));
-                    } else if (cp_info instanceof ConstantInterfaceMethodrefInfo) {
-                        sb.append(this.getDescr_InterfaceMethodref((ConstantInterfaceMethodrefInfo) cp_info));
-                    } else if (cp_info instanceof ConstantNameAndTypeInfo) {
-                        sb.append(this.getDescr_NameAndType(
-                                (ConstantNameAndTypeInfo) cp_info,
-                                ClassFile.Descr_NameAndType.RAW));
-                    } else if (cp_info instanceof ConstantMethodTypeInfo) {
-                        ConstantMethodTypeInfo mti = (ConstantMethodTypeInfo) cp_info;
-                        sb.append(this.getDescr_Utf8((ConstantUtf8Info) ClassFile.this.constant_pool[mti.descriptor_index.value]));
-                    } else if (cp_info instanceof ConstantDynamicInfo) {
-                        sb.append("bootstrap_method_attr_index = ").append(((ConstantDynamicInfo) cp_info).bootstrap_method_attr_index.value);
-                        sb.append(", name_and_type_index = ").append(this.getCPDescr(((ConstantDynamicInfo) cp_info).name_and_type_index.value));
-                    } else if (cp_info instanceof ConstantInvokeDynamicInfo) {
-                        sb.append("bootstrap_method_attr_index = ").append(((ConstantInvokeDynamicInfo) cp_info).bootstrap_method_attr_index.value);
-                        sb.append(", name_and_type_index = ").append(this.getCPDescr(((ConstantInvokeDynamicInfo) cp_info).name_and_type_index.value));
-                    } else if (cp_info instanceof ConstantMethodHandleInfo) {
-                        sb.append("reference_kind = ").append(ConstantMethodHandleInfo.ReferenceKind.name(((ConstantMethodHandleInfo) cp_info).reference_kind.value));
-                        sb.append(", reference_index = ").append(this.getCPDescr(((ConstantMethodHandleInfo) cp_info).reference_index.value));
-                    } else if (cp_info instanceof ConstantModuleInfo) {
-                        sb.append(this.getDescr_Utf8((ConstantUtf8Info) ClassFile.this.constant_pool[((ConstantModuleInfo) cp_info).name_index.value]));
-                    } else if (cp_info instanceof ConstantPackageInfo) {
-                        sb.append(this.getDescr_Utf8((ConstantUtf8Info) ClassFile.this.constant_pool[((ConstantPackageInfo) cp_info).name_index.value]));
-                    } else {
-                        sb.append("!!! Un-recognized CP type.");
-                    }
-                } // End if
-            } else {
-                sb.append("ERROR - Index (" + index + ") out of bound of constant_pool (" + ClassFile.this.constant_pool.length + ")");
-            }
-
-            return sb.toString();
-        }
-
-        private String getDescr_Utf8(final ConstantUtf8Info info) {
-            return info.getValue();
-        }
-
-        private String getDescr_Class(final ConstantClassInfo info) {
-            // The value of the name_index item must be a valid index into the constant_pool table.
-            // The constant_pool entry at that index must be a CONSTANT_Utf8_info structure
-            // representing a valid fully qualified class or interface name encoded in internal form.
-            return SignatureConvertor.ParseClassSignature(this.getDescr_Utf8(
-                    (ConstantUtf8Info) ClassFile.this.constant_pool[info.name_index.value]));
-        }
-
-        private String getDescr_String(final ConstantStringInfo info) {
-            // The value of the string_index item must be a valid index into the constant_pool table.
-            // The constant_pool entry at that index must be a CONSTANT_Utf8_info structure
-            // representing the sequence of characters to which the String object is to be initialized.
-            return SignatureConvertor.ParseClassSignature(this.getDescr_Utf8(
-                    (ConstantUtf8Info) ClassFile.this.constant_pool[info.string_index.value]));
-        }
-
-        private String getDescr_Fieldref(final ConstantFieldrefInfo info) {
-            return this.getDescr_ref(
-                    info.class_index.value,
-                    info.name_and_type_index.value,
-                    ClassFile.Descr_NameAndType.FIELD);
-        }
-
-        private String getDescr_Methodref(final ConstantMethodrefInfo info) {
-            return this.getDescr_ref(
-                    info.class_index.value,
-                    info.name_and_type_index.value,
-                    ClassFile.Descr_NameAndType.METHOD);
-        }
-
-        private String getDescr_InterfaceMethodref(final ConstantInterfaceMethodrefInfo info) {
-            return this.getDescr_ref(
-                    info.class_index.value,
-                    info.name_and_type_index.value,
-                    ClassFile.Descr_NameAndType.METHOD);
-        }
-
-        private String getDescr_ref(final int classindex, final int natindex, final ClassFile.Descr_NameAndType type) {
-            final StringBuilder sb = new StringBuilder();
-            sb.append(this.getDescr_Class((ConstantClassInfo) ClassFile.this.constant_pool[classindex]));
-            sb.append(".");
-            sb.append(this.getDescr_NameAndType((ConstantNameAndTypeInfo) ClassFile.this.constant_pool[natindex], type));
-
-            return sb.toString();
-        }
-
-        private String getDescr_NameAndType(final ConstantNameAndTypeInfo info, final ClassFile.Descr_NameAndType format) {
-            final StringBuilder sb = new StringBuilder();
-            String type;
-
-            sb.append(this.getDescr_Utf8((ConstantUtf8Info) ClassFile.this.constant_pool[info.name_index.value]));
-            sb.append(", ");
-            type = this.getDescr_Utf8((ConstantUtf8Info) ClassFile.this.constant_pool[info.descriptor_index.value]);
-
-            switch (format) {
-                case RAW:
-                    sb.append(type);
-                    break;
-
-                case FIELD:
-                    try {
-                        sb.append("type = ");
-                        sb.append(SignatureConvertor.FieldDescriptorExtractor(type).toString());
-                    } catch (FileFormatException ex) {
-                        Logger.getLogger(ClassFile.class.getName()).log(Level.SEVERE, null, ex);
-
-                        sb.append(type);
-                        sb.append(" !!! Un-recognized type");
-                    }
-                    break;
-
-                case METHOD:
-                    final StringBuilder sb_mtd = new StringBuilder();
-                    try {
-                        sb_mtd.append("parameter = ");
-                        sb_mtd.append(SignatureConvertor.MethodParameters2Readable(type));
-                        sb_mtd.append(", returns = ");
-                        sb_mtd.append(SignatureConvertor.MethodReturnTypeExtractor(type).toString());
-
-                        sb.append(sb_mtd);
-                    } catch (FileFormatException ex) {
-                        Logger.getLogger(ClassFile.class.getName()).log(Level.SEVERE, null, ex);
-
-                        sb.append(type);
-                        sb.append(" !!! Un-recognized type");
-                    }
-                    break;
-                default:
-                    break;
-            }
-
-            return sb.toString();
-        }
-    }
-
     /**
      * Version numbers of a class file. Together, a major and a minor version
      * number determine the version of the class file format. If a class file

FormatCLASS/src/main/java/org/freeinternals/format/classfile/Opcode.java

@@ -1471,7 +1471,7 @@ protected InstructionParsed parse(final int curPos, final PosDataInputStream pdi
                     parsed.lookupSwitch.mapoffsets.put(pdis.readInt(), pdis.readInt());
                 }
 
-                parsed.opCodeText = String.format("%s  %s", this.name(), parsed.lookupSwitch.toString(curPos));
+                parsed.opCodeText = String.format("%s %s", this.name(), parsed.lookupSwitch.toString(curPos));
                 return parsed;
             }
         },
@@ -2096,7 +2096,7 @@ public static class LookupSwitch {
 
         public String toString(int currentOffset) {
             final StringBuilder sb = new StringBuilder(256);
-            sb.append("- ").append(this.npairs).append(" Pairs");
+            sb.append('(').append(this.npairs).append(" Pairs)");
             this.mapoffsets.keySet().forEach((key) -> {
                 Integer value = this.mapoffsets.get(key);
                 sb.append(String.format("\n    case %d. jump to %d (relative offset = %d)", key, value + currentOffset, value));
@@ -2130,7 +2130,7 @@ public static class TableSwitch {
 
         public String toString(int currentOffset) {
             final StringBuilder sb = new StringBuilder(256);
-            sb.append("- from ").append(this.lowbyte).append(" to ").append(this.highbyte);
+            sb.append(" (from ").append(this.lowbyte).append(" to ").append(this.highbyte).append(')');
             this.jumpoffsets.keySet().forEach((key) -> {
                 Integer value = this.jumpoffsets.get(key);
                 sb.append(String.format("\n    case %d. jump to %d (relative offset = %d) ", key, value + currentOffset, value));

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/CPInfo.java

@@ -38,6 +38,11 @@
  */
 public abstract class CPInfo extends FileComponent {
 
+    /**
+     * Warning message for un-recognized type.
+     */
+    protected static final String UNRECOGNIZED_TYPE = " !!! Un-recognized type";
+
     /**
      * Each item in the {@link ClassFile#constant_pool} table must begin with a
      * 1-byte {@link #tag} indicating the kind of <code>cp_info</code> entry.

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/ConstantClassInfo.java

@@ -59,7 +59,6 @@ public String toString(CPInfo[] constant_pool) {
         // The value of the name_index item must be a valid index into the constant_pool table.
         // The constant_pool entry at that index must be a CONSTANT_Utf8_info structure
         // representing a valid fully qualified class or interface name encoded in internal form.
-        final String classtype = SignatureConvertor.ParseClassSignature(((ConstantUtf8Info) constant_pool[this.name_index.value]).getValue());
-        return this.getName() + ". " + classtype;
+        return SignatureConvertor.ParseClassSignature(((ConstantUtf8Info) constant_pool[this.name_index.value]).getValue());
     }
 }

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/ConstantDoubleInfo.java

@@ -62,6 +62,6 @@ public String getDescription() {
 
     @Override
     public String toString(CPInfo[] constant_pool) {
-        return this.getName() + ". " + this.doubleValue;
+        return String.valueOf(this.doubleValue);
     }
 }

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/ConstantDynamicInfo.java

@@ -84,6 +84,10 @@ public String getDescription() {
 
     @Override
     public String toString(CPInfo[] constant_pool) {
-        return null;
+        // TODO Improve this logic with test case
+        final StringBuilder sb = new StringBuilder(64);
+        sb.append("bootstrap_method_attr_index = ").append(this.bootstrap_method_attr_index.value);
+        sb.append(", name_and_type_index = ").append(constant_pool[this.name_and_type_index.value].toString(constant_pool));
+        return sb.toString();
     }
 }

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/ConstantFieldrefInfo.java

@@ -7,9 +7,13 @@
 package org.freeinternals.format.classfile.constant;
 
 import java.io.IOException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import org.freeinternals.commonlib.core.PosDataInputStream;
+import org.freeinternals.format.FileFormatException;
 import org.freeinternals.format.classfile.ClassFile;
 import org.freeinternals.format.classfile.JavaSEVersion;
+import org.freeinternals.format.classfile.SignatureConvertor;
 
 /**
  * The class for the {@code CONSTANT_Fieldref_info} structure in constant pool.
@@ -32,6 +36,32 @@
 public class ConstantFieldrefInfo extends ConstantRefInfo {
 
     ConstantFieldrefInfo(final PosDataInputStream posDataInputStream) throws IOException {
-        super(CPInfo.ConstantType.CONSTANT_Fieldref.tag, posDataInputStream, ConstantType.CONSTANT_Fieldref.name(), ClassFile.Version.Format_45_3, JavaSEVersion.Version_1_0_2);
+        super(CPInfo.ConstantType.CONSTANT_Fieldref.tag, posDataInputStream, ClassFile.Version.Format_45_3, JavaSEVersion.Version_1_0_2);
+    }
+
+    @Override
+    public String getName() {
+        return ConstantType.CONSTANT_Fieldref.name();
+    }
+
+    @Override
+    public String toString(CPInfo[] constant_pool) {
+        // Class
+        String clazz = constant_pool[this.class_index.value].toString(constant_pool);
+
+        // Name and Type
+        ConstantNameAndTypeInfo nameType = (ConstantNameAndTypeInfo) constant_pool[this.name_and_type_index.value];
+        String name = constant_pool[nameType.name_index.value].toString(constant_pool);
+        String type = constant_pool[nameType.descriptor_index.value].toString(constant_pool);
+        String typeDesc;
+
+        try {
+            typeDesc = SignatureConvertor.FieldDescriptorExtractor(type).toString();
+        } catch (FileFormatException ex) {
+            typeDesc = type + UNRECOGNIZED_TYPE;
+            Logger.getLogger(this.getClass().getName()).log(Level.SEVERE, "Failed to parse the field type: " + type, ex);
+        }
+
+        return String.format("%s.%s : %s", clazz, name, typeDesc);
     }
 }

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/ConstantFloatInfo.java

@@ -58,6 +58,6 @@ public String getDescription() {
 
     @Override
     public String toString(CPInfo[] constant_pool) {
-        return this.getName() + ". " + this.floatValue;
+        return String.valueOf(this.floatValue);
     }
 }

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/ConstantIntegerInfo.java

@@ -57,6 +57,6 @@ public String getDescription() {
 
     @Override
     public String toString(CPInfo[] constant_pool) {
-        return String.format("%s. %d", this.getName(), this.integerValue);
+        return String.valueOf(this.integerValue);
     }
 }

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/ConstantInterfaceMethodrefInfo.java

@@ -34,6 +34,16 @@
 public class ConstantInterfaceMethodrefInfo extends ConstantRefInfo {
 
     ConstantInterfaceMethodrefInfo(final PosDataInputStream posDataInputStream) throws IOException {
-        super(CPInfo.ConstantType.CONSTANT_InterfaceMethodref.tag, posDataInputStream, ConstantType.CONSTANT_InterfaceMethodref.name(), ClassFile.Version.Format_45_3, JavaSEVersion.Version_1_0_2);
+        super(CPInfo.ConstantType.CONSTANT_InterfaceMethodref.tag, posDataInputStream, ClassFile.Version.Format_45_3, JavaSEVersion.Version_1_0_2);
+    }
+
+    @Override
+    public String getName() {
+        return ConstantType.CONSTANT_InterfaceMethodref.name();
+    }
+
+    @Override
+    public String toString(CPInfo[] constant_pool) {
+        return super.toString4Method(constant_pool);
     }
 }

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/ConstantInvokeDynamicInfo.java

@@ -78,6 +78,10 @@ public String getDescription() {
 
     @Override
     public String toString(CPInfo[] constant_pool) {
-        return null;
+        // TODO Improve this logic with test case
+        final StringBuilder sb = new StringBuilder(64);
+        sb.append("bootstrap_method_attr_index = ").append(this.bootstrap_method_attr_index.value);
+        sb.append(", name_and_type_index = ").append(constant_pool[this.name_and_type_index.value].toString(constant_pool));
+        return sb.toString();
     }
 }

FormatCLASS/src/main/java/org/freeinternals/format/classfile/constant/ConstantLongInfo.java

@@ -62,6 +62,6 @@ public String getDescription() {
 
     @Override
     public String toString(CPInfo[] constant_pool) {
-        return this.getName() + ". " + this.longValue;
+        return String.valueOf(this.longValue);
     }
 }