com.sun.codemodel.JFormatter Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2022 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package com.sun.codemodel;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
/**
* This is a utility class for managing indentation and other basic
* formatting for PrintWriter.
*/
public final class JFormatter {
/* all classes and ids encountered during the collection mode */
/* map from short type name to ReferenceList (list of JClass and ids sharing that name) */
private HashMap collectedReferences;
/** set of imported types (including package java types, eventhough we won't generate imports for them) */
private HashSet importedClasses;
private enum Mode {
/**
* Collect all the type names and identifiers.
* In this mode we don't actually generate anything.
*/
COLLECTING,
/**
* Print the actual source code.
*/
PRINTING
}
/**
* The current running mode.
* Set to PRINTING so that a casual client can use a formatter just like before.
*/
private Mode mode = Mode.PRINTING;
/**
* Current number of indentation strings to print
*/
private int indentLevel;
/**
* String to be used for each indentation.
* Defaults to four spaces.
*/
private final String indentSpace;
/**
* Stream associated with this JFormatter
*/
private final PrintWriter pw;
private final Map classNameReplacer;
/**
* Creates a JFormatter.
*
* @param s
* PrintWriter to JFormatter to use.
*
* @param space
* Incremental indentation string, similar to tab value.
*/
public JFormatter(PrintWriter s, String space) {
this(s, space, Collections.emptyMap());
}
/**
* Creates a JFormatter.
*
* @param s
* PrintWriter to JFormatter to use.
*
* @param space
* Incremental indentation string, similar to tab value.
*
* @param classNameReplacer
* Class names to replace.
*/
public JFormatter(PrintWriter s, String space, Map classNameReplacer) {
pw = s;
indentSpace = space;
collectedReferences = new HashMap<>();
//ids = new HashSet();
importedClasses = new HashSet<>();
this.classNameReplacer = classNameReplacer;
}
/**
* Creates a formatter with default incremental indentations of
* four spaces.
*/
public JFormatter(PrintWriter s) {
this(s, " ", Collections.emptyMap());
}
/**
* Creates a formatter with default incremental indentations of
* four spaces and replaces the class names in classNameReplacer.
*/
public JFormatter(PrintWriter s, Map classNameReplacer) {
this(s, " ", classNameReplacer);
}
/**
* Creates a formatter with default incremental indentations of
* four spaces.
*/
public JFormatter(Writer w) {
this(new PrintWriter(w));
}
/**
* Closes this formatter.
*/
public void close() {
pw.close();
}
/**
* Returns true if we are in the printing mode,
* where we actually produce text.
*
* The other mode is the "collecting mode'
*/
public boolean isPrinting() {
return mode == Mode.PRINTING;
}
/**
* Decrement the indentation level.
*/
public JFormatter o() {
indentLevel--;
return this;
}
/**
* Increment the indentation level.
*/
public JFormatter i() {
indentLevel++;
return this;
}
private boolean needSpace(char c1, char c2) {
if ((c1 == ']') && (c2 == '{')) return true;
if (c1 == ';') return true;
if (c1 == CLOSE_TYPE_ARGS) {
// e.g., "public Foo test;"
// but not "new Foo()"
return c2 != '(';
}
if ((c1 == ')') && (c2 == '{')) return true;
if ((c1 == ',') || (c1 == '=')) return true;
if (c2 == '=') return true;
if (Character.isDigit(c1)) {
return (c2 != '(') && (c2 != ')') && (c2 != ';') && (c2 != ',');
}
if (Character.isJavaIdentifierPart(c1)) {
switch (c2) {
case '{':
case '}':
case '+':
case '>':
case '@':
return true;
default:
return Character.isJavaIdentifierStart(c2);
}
}
if (Character.isJavaIdentifierStart(c2)) {
switch (c1) {
case ']':
case ')':
case '}':
case '+':
return true;
default:
return false;
}
}
if (Character.isDigit(c2)) {
return c1 != '(';
}
return false;
}
private char lastChar = 0;
private boolean atBeginningOfLine = true;
private void spaceIfNeeded(char c) {
if (atBeginningOfLine) {
for (int i = 0; i < indentLevel; i++)
pw.print(indentSpace);
atBeginningOfLine = false;
} else if ((lastChar != 0) && needSpace(lastChar, c))
pw.print(' ');
}
/**
* Print a char into the stream
*
* @param c the char
*/
public JFormatter p(char c) {
if(mode==Mode.PRINTING) {
if(c==CLOSE_TYPE_ARGS) {
pw.print('>');
} else {
spaceIfNeeded(c);
pw.print(c);
}
lastChar = c;
}
return this;
}
/**
* Print a String into the stream
*
* @param s the String
*/
public JFormatter p(String s) {
if(mode==Mode.PRINTING) {
spaceIfNeeded(s.charAt(0));
pw.print(s);
lastChar = s.charAt(s.length() - 1);
}
return this;
}
public JFormatter t(JType type) {
if(type.isReference()) {
return t((JClass)type);
} else {
return g(type);
}
}
/**
* Print a type name.
*
*
* In the collecting mode we use this information to
* decide what types to import and what not to.
*/
public JFormatter t(JClass type) {
switch(mode) {
case PRINTING:
// many of the JTypes in this list are either primitive or belong to package java
// so we don't need a FQCN
if(importedClasses.contains(type)) {
p(type.name()); // FQCN imported or not necessary, so generate short name
} else {
if(type.outer()!=null) {
t(type.outer()).p('.').p(type.name());
} else {
p(renameClassName(type.fullName())); // collision was detected, so generate FQCN
}
}
break;
case COLLECTING:
final String shortName = type.name();
if(collectedReferences.containsKey(shortName)) {
collectedReferences.get(shortName).add(type);
} else {
ReferenceList tl = new ReferenceList();
tl.add(type);
collectedReferences.put(shortName, tl);
}
break;
}
return this;
}
private String renameClassName(String fullName) {
for (Entry pair : classNameReplacer.entrySet()) {
if (fullName.startsWith(pair.getKey())) {
return fullName.replaceFirst(pair.getKey(), pair.getValue());
}
}
return fullName;
}
/**
* Print an identifier
*/
public JFormatter id(String id) {
switch(mode) {
case PRINTING:
p(id);
break;
case COLLECTING:
// see if there is a type name that collides with this id
if(collectedReferences.containsKey(id)) {
if( !collectedReferences.get(id).getClasses().isEmpty() ) {
for( JClass type : collectedReferences.get(id).getClasses() ) {
if (type.outer()!=null) {
collectedReferences.get(id).setId(false);
return this;
}
}
}
collectedReferences.get(id).setId(true);
} else {
// not a type, but we need to create a place holder to
// see if there might be a collision with a type
ReferenceList tl = new ReferenceList();
tl.setId(true);
collectedReferences.put(id, tl);
}
break;
}
return this;
}
/**
* Print a new line into the stream
*/
public JFormatter nl() {
if(mode==Mode.PRINTING) {
pw.println();
lastChar = 0;
atBeginningOfLine = true;
}
return this;
}
/**
* Cause the JGenerable object to generate source for iteself
*
* @param g the JGenerable object
*/
public JFormatter g(JGenerable g) {
g.generate(this);
return this;
}
/**
* Produces {@link JGenerable}s separated by ','
*/
public JFormatter g(Collection list) {
boolean first = true;
if(!list.isEmpty()) {
for (JGenerable item : list) {
if (!first)
p(',');
g(item);
first = false;
}
}
return this;
}
/**
* Cause the JDeclaration to generate source for itself
*
* @param d the JDeclaration object
*/
public JFormatter d(JDeclaration d) {
d.declare(this);
return this;
}
/**
* Cause the JStatement to generate source for itself
*
* @param s the JStatement object
*/
public JFormatter s(JStatement s) {
s.state(this);
return this;
}
/**
* Cause the JVar to generate source for itself
*
* @param v the JVar object
*/
public JFormatter b(JVar v) {
v.bind(this);
return this;
}
/**
* Generates the whole source code out of the specified class.
*/
void write(JDefinedClass c) {
// first collect all the types and identifiers
mode = Mode.COLLECTING;
d(c);
javaLang = c.owner()._package("java.lang");
// collate type names and identifiers to determine which types can be imported
for( ReferenceList tl : collectedReferences.values() ) {
if(!tl.collisions(c) && !tl.isId()) {
assert tl.getClasses().size() == 1;
// add to list of collected types
importedClasses.add(tl.getClasses().get(0));
}
}
// the class itself that we will be generating is always accessible
importedClasses.add(c);
// then print the declaration
mode = Mode.PRINTING;
assert c.parentContainer().isPackage() : "this method is only for a pacakge-level class";
JPackage pkg = (JPackage) c.parentContainer();
if (!pkg.isUnnamed()) {
nl().d(pkg);
nl();
}
// generate import statements
JClass[] imports = importedClasses.toArray(new JClass[0]);
Arrays.sort(imports);
for (JClass clazz : imports) {
// suppress import statements for primitive types, built-in types,
// types in the root package, and types in
// the same package as the current type
if(!supressImport(clazz, c)) {
if (clazz instanceof JNarrowedClass) {
clazz = clazz.erasure();
}
p("import").p(renameClassName(clazz.fullName())).p(';').nl();
}
}
nl();
d(c);
}
/**
* determine if an import statement should be supressed
*
* @param clazz JType that may or may not have an import
* @param c JType that is the current class being processed
* @return true if an import statement should be suppressed, false otherwise
*/
private boolean supressImport(JClass clazz, JClass c) {
if (clazz instanceof JNarrowedClass) {
clazz = clazz.erasure();
}
if (clazz instanceof JAnonymousClass) {
clazz = clazz._extends();
}
if(clazz._package().isUnnamed())
return true;
final String packageName = clazz._package().name();
if(packageName.equals("java.lang"))
return true; // no need to explicitly import java.lang classes
if (clazz._package() == c._package()){
// inner classes require an import stmt.
// All other pkg local classes do not need an
// import stmt for ref.
return clazz.outer() == null; // no need to explicitly import a class into itself
}
return false;
}
private JPackage javaLang;
/**
* Special character token we use to differentiate '{@literal >}' as an operator and
* '{@literal >}' as the end of the type arguments. The former uses '{@literal >}' and it requires
* a preceding whitespace. The latter uses this, and it does not have a preceding
* whitespace.
*/
/*package*/ static final char CLOSE_TYPE_ARGS = '\uFFFF';
/**
* Used during the optimization of class imports.
*
* List of {@link JClass}es whose short name is the same.
*
* @author [email protected]
*/
final class ReferenceList {
private final ArrayList classes = new ArrayList<>();
/** true if this name is used as an identifier (like a variable name.) **/
private boolean id;
/**
* Returns true if the symbol represented by the short name
* is "importable".
*/
public boolean collisions(JDefinedClass enclosingClass) {
// special case where a generated type collides with a type in package java
// more than one type with the same name
if(classes.size() > 1)
return true;
// an id and (at least one) type with the same name
if(id && classes.size() != 0)
return true;
for(JClass c : classes) {
if (c instanceof JAnonymousClass) {
c = c._extends();
}
if(c._package()==javaLang) {
// make sure that there's no other class with this name within the same package
Iterator itr = enclosingClass._package().classes();
while(itr.hasNext()) {
// even if this is the only "String" class we use,
// if the class called "String" is in the same package,
// we still need to import it.
JDefinedClass n = itr.next();
if(n.name().equals(c.name()))
return true; //collision
}
}
if(c.outer()!=null)
return true; // avoid importing inner class to work around 6431987. Also see jaxb issue 166
}
return false;
}
public void add(JClass clazz) {
if(!classes.contains(clazz))
classes.add(clazz);
}
public List getClasses() {
return classes;
}
public void setId(boolean value) {
id = value;
}
/**
* Return true iff this is strictly an id, meaning that there
* are no collisions with type names.
*/
public boolean isId() {
return id && classes.size() == 0;
}
}
}