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Next generation template engine for Java
/**
* Copyright 2013-2016 Guoqiang Chen, Shanghai, China. All rights reserved.
*
* Author: Guoqiang Chen
* Email: [email protected]
* WebURL: https://github.com/subchen
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jetbrick.template.parser.ast;
import java.io.IOException;
import java.nio.charset.Charset;
import jetbrick.bean.FieldInfo;
import jetbrick.bean.KlassInfo;
import jetbrick.template.runtime.*;
import jetbrick.util.JdkUtils;
public final class AstText extends AstStatement {
private String text;
private volatile TextEncoder encoder;
private int line;
public AstText(String text, int line) {
this.text = text;
this.line = line;
}
public String getText() {
return text;
}
public int getLine() {
return line;
}
// --------------------------------------------------------------------
protected boolean isEmpty() {
return text == null || text.length() == 0;
}
protected void trimDirectiveWhitespaces(boolean trimLeft, boolean trimRight, boolean keepLeftNewLine) {
if (text == null || text.length() == 0) {
return;
}
int len = text.length();
int lpos = 0;
boolean trimedNewLine = false; // 是否删除了一个 new line
if (trimLeft) {
for (int i = 0; i < len; i++) {
char c = text.charAt(i);
if (c == ' ' || c == '\t') {
continue;
} else if (c == '\r') {
if (keepLeftNewLine) {
lpos = i;
break;
} else {
trimedNewLine = true;
int n = i + 1;
if (n < len && text.charAt(n) == '\n') {
lpos = n + 1; // window: \r\n
} else {
lpos = n; // mac: \r
}
break;
}
} else if (c == '\n') {
if (keepLeftNewLine) {
lpos = i;
} else {
trimedNewLine = true;
lpos = i + 1; // linux: \n
}
break;
} else {
break;
}
}
}
int rpos = len;
if (trimRight) {
for (int i = len - 1; i >= 0; i--) {
char c = text.charAt(i);
if (c == ' ' || c == '\t') {
continue;
} else if (c == '\n' || c == '\r') {
rpos = i + 1;
break;
} else {
break;
}
}
}
if (lpos < rpos) {
text = text.substring(lpos, rpos);
} else {
text = null;
}
if (trimedNewLine) {
line++;
}
}
protected void trimDirectiveComments(boolean trimLeft, boolean trimRight, String prefix, String suffix) {
if (text == null || text.length() == 0) {
return;
}
int text_len = text.length();
int prefix_len = prefix.length();
int suffix_len = suffix.length();
int lpos = 0;
if (trimLeft) {
for (int i = 0; i < text_len; i++) {
char c = text.charAt(i);
if (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
continue;
} else {
boolean matched = true;
int j = 0;
while (i < text_len && j < suffix_len) {
if (text.charAt(i) != suffix.charAt(j)) {
matched = false;
break;
}
i++;
j++;
}
if (matched) {
lpos = i;
}
break;
}
}
}
int rpos = text_len;
if (trimRight) {
for (int i = text_len - 1; i >= 0; i--) {
char c = text.charAt(i);
if (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
continue;
} else {
boolean matched = true;
int j = prefix_len - 1;
while (i >= 0 && j >= 0) {
if (text.charAt(i) != prefix.charAt(j)) {
matched = false;
break;
}
i--;
j--;
}
if (matched) {
rpos = i + 1;
}
break;
}
}
}
if (lpos < rpos) {
text = text.substring(lpos, rpos);
} else {
text = null;
}
}
protected void trimLastNewLine() {
if (text == null || text.length() == 0) {
return;
}
int length = text.length();
if (text.charAt(length - 1) == '\n') {
length--;
if (length > 0 && text.charAt(length - 1) == '\r') {
length--;
}
}
text = text.substring(0, length);
}
// --------------------------------------------------------------------
@Override
public void execute(InterpretContext ctx) throws InterpretException {
JetWriter os = ctx.getWriter();
if (encoder == null) {
synchronized (this) {
// double check
if (encoder == null) {
if (os.isStreaming()) {
encoder = new ByteArrayEncoder(text, os.getCharset());
} else {
if (JdkUtils.IS_AT_LEAST_JAVA_7) {
encoder = new Jdk7CharArrayEncoder(text);
} else {
encoder = new Jdk6CharArrayEncoder(text);
}
}
text = null; // free
}
}
}
try {
encoder.writeTo(os);
} catch (IOException e) {
throw new IllegalStateException(e);
}
}
@Override
public String toString() {
return text;
}
// --------------------------------------------------------------------
static interface TextEncoder {
public void writeTo(JetWriter os) throws IOException;
}
static final class ByteArrayEncoder implements TextEncoder {
private final byte[] bytes;
public ByteArrayEncoder(String text, Charset charset) {
this.bytes = text.getBytes(charset);
}
@Override
public void writeTo(JetWriter os) throws IOException {
os.print(bytes, 0, bytes.length);
}
}
// 从 JDK7 开始，String.class 不在提供 offset 和 count
static final KlassInfo KLASS_STRING = KlassInfo.create(String.class);
static final FieldInfo FIELD_STRING_VALUE = KLASS_STRING.getDeclaredField("value");
static final FieldInfo FIELD_STRING_OFFSET = KLASS_STRING.getDeclaredField("offset");
static final FieldInfo FIELD_STRING_COUNT = KLASS_STRING.getDeclaredField("count");
static final class Jdk7CharArrayEncoder implements TextEncoder {
final char[] chars;
public Jdk7CharArrayEncoder(String text) {
this.chars = (char[]) FIELD_STRING_VALUE.get(text);
}
@Override
public void writeTo(JetWriter os) throws IOException {
os.print(chars, 0, chars.length);
}
}
static final class Jdk6CharArrayEncoder implements TextEncoder {
final char[] chars;
final int offset;
final int count;
public Jdk6CharArrayEncoder(String text) {
this.chars = (char[]) FIELD_STRING_VALUE.get(text);
this.offset = (Integer) FIELD_STRING_OFFSET.get(text);
this.count = (Integer) FIELD_STRING_COUNT.get(text);
}
@Override
public void writeTo(JetWriter os) throws IOException {
os.print(chars, offset, count);
}
}
}