Java examples for Reflection:Field
print Fields from an Object via Reflection
//package com.java2s; import java.lang.reflect.Field; import java.lang.reflect.Modifier; import java.util.Collection; public class Main { public static void main(String[] argv) { Object o = "java2s.com"; StringBuilder sb = new StringBuilder(); int indentation = 42; printFields(o, sb, indentation); }//from w w w . j a v a2 s . c om private static final void printFields(Object o, StringBuilder sb, int indentation) { if (o == null) { sb.append("null"); return; } if (indentation > 12) { sb.append(o); return; } if (o instanceof Object[]) { Object[] os = (Object[]) o; sb.append("(").append(os.length).append(")[\n"); int i = 0; for (Object o2 : os) { generateIndentation(sb, indentation); sb.append(i++); sb.append(" => "); printFields(o2, sb, indentation + 2); sb.append("\n"); } i = sb.length() - 1; if (os.length == 0) sb.setCharAt(i, ']'); else { generateIndentation(sb, indentation - 2); sb.append(']'); } return; } if (o instanceof Collection<?>) { Collection<? extends Object> os = (Collection<?>) o; sb.append("(").append(os.size()).append(")[\n"); int i = 0; for (Object o2 : os) { generateIndentation(sb, indentation); sb.append(i++); sb.append(" => "); printFields(o2, sb, indentation + 2); sb.append("\n"); } i = sb.length() - 1; if (os.size() == 0) sb.setCharAt(i, ']'); else { generateIndentation(sb, indentation - 2); sb.append(']'); } return; } if (o.getClass().getName().startsWith("java") && !o.getClass().getName().equals("java.lang.Object")) { sb.append(o); return; } sb.append("{\n"); for (Field f : o.getClass().getDeclaredFields()) { f.setAccessible(true); if (f.isSynthetic() || (f.getModifiers() & Modifier.STATIC) > 0) continue; try { generateIndentation(sb, indentation); sb.append(f.getName()).append("="); printFields(f.get(o), sb, indentation + 2); sb.append("\n"); } catch (Exception e) { } } int i = sb.length() - 2; if (sb.charAt(i) == '{') sb.setCharAt(i + 1, '}'); else { generateIndentation(sb, indentation - 2); sb.append("}"); } } private static final void generateIndentation(StringBuilder sb, int indentation) { while ((indentation = indentation - 2) >= 0) { sb.append(" "); } } }