http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); %-'U9e KN
} ? sewU9*
for(int i=0;i<nEndPos.length-1;i++) L2h+[f
{ 6~/H#8Kdn
nEndPos = nStartPos[i+1]; P*T)/A%4
} #EM'=Q%TO
nEndPos[nEndPos.length-1] = nFileLength; #129 i2
} v/haUPWF\
} y14@9<~9
pq&c]8H
Go67VqJr
//启动子线程 TnaIRJ\B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L wu;y@[
for(int i=0;i<nStartPos.length;i++) Fszk?0T
{ B&$89]gs|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5Q}@Y3 i=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2$ rq
nStartPos,nEndPos,i); d?P aZz{4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0Yjy
fileSplitterFetch.start(); &4[iC/}
} A{o{o++
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *sG<w%%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -/qrEKQ0U?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o<'gM]$
nEndPos = " + nFileLength); ]/']{*T1
// fileSplitterFetch[nPos.length-1].start(); D_)vGvv3;.
T:&+#0<
N.`]D)57
//等待子线程结束 @&W?e?O ~G
//int count = 0; C(P$,;6
//是否结束while循环 ~<U3KB
boolean breakWhile = false; t}FMBGo[
{LeEnh-
k WtUj
while(!bStop) >dl!Ep
{ N9ufTlq s
write_nPos(); ybG)=0
Utility.sleep(500); i=a LC*@
breakWhile = true; @6!JW(,]\
<<1oc{i
=KZ4:d5
for(int i=0;i<nStartPos.length;i++) Vel;t<1
{ u@EM,o
if(!fileSplitterFetch.bDownOver) {EUH#':
{ IXN4?=)I
breakWhile = false; M5V1j(URE
break; g3XAs@
} A!kyga6F5
} D+3Y.r9
if(breakWhile) aVYUk7_<
break; <X |h*
bH{aI:9Fb
c" 7pf T
//count++; gsp7N
//if(count>4) OQQ9R?Ll{
// siteStop(); k#(cZ
} QA(,K}z~^S
^IpiNY/%Q
1#<E]<='t
System.err.println("文件下载结束！"); }(K6 YL
} hI8C XG
catch(Exception e){e.printStackTrace ();} /<$"c"UQ
} d"UW38K{
,no:6&#
WLLv a<{
//获得文件长度 eNFUjDm
public long getFileSize() ODEXQl}R
{ 2>k)=hl:
int nFileLength = -1; ^gyp- !
try{ y^\#bpq&\
URL url = new URL(siteInfoBean.getSSiteURL()); @RIEO%S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cpcd`y=IN
httpConnection.setRequestProperty("User-Agent","NetFox"); 0AKwZ' &H
E3skC%}
=.hDf<U
int responseCode=httpConnection.getResponseCode(); 1}E@lOc
if(responseCode>=400) A*~1Uz\t
{ {UBQ?7.jE
processErrorCode(responseCode); Bedjw =B
return -2; //-2 represent access is error ]P$DAi
} }Xi#x*-D
?ljod6
Ne7{{1
String sHeader; ;x^,t@ xge
<WJ0St
}%ThnFFBw
for(int i=1;;i++) eF^"{a3b
{ IJY5wP1"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); i q:Q$z&
//Utility.log(in.readLine()); ^u!Tyb8Dk
sHeader=httpConnection.getHeaderFieldKey(i); PAU+C_P
if(sHeader!=null) @a\SR'8
{ vCSB8R
if(sHeader.equals("Content-Length")) FT>~ES]cQd
{ aX)./
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JvL'gJ$70
break; D!a5#+\C
} q{/Jw"e
} vfUfrk@D~
else Gc!8v}[7J
break; <]^;/2.B
} :V~*vLvR
} c dbSv=r
catch(IOException e){e.printStackTrace ();} wrYQ=u#Z
catch(Exception e){e.printStackTrace ();} rDX'oP:
v-fi9$#^
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Utility.log(nFileLength); iv+jv2ZF%
d5"EvT
Q@wq }vc!
return nFileLength; P`dHR;Y0
} Jav2A6a
RIEv*2_O
pEj^x[b`^
//保存下载信息（文件指针位置） pptM&Y
private void write_nPos() 6//FZ:q
{ 7E3SvC|M
try{ qf`xH"$
output = new DataOutputStream(new FileOutputStream(tmpFile)); p <=%
output.writeInt(nStartPos.length); !NLvo_[Y
for(int i=0;i<nStartPos.length;i++) 0nn]]B@l
{ yCCw<?
// output.writeLong(nPos); TUUE(sLA
output.writeLong(fileSplitterFetch.nStartPos); NS4'IR=;E!
output.writeLong(fileSplitterFetch.nEndPos); r`R~{;oT
} 2HGD{;6>v{
output.close(); G7Abhb,
} N@*wi"Q
catch(IOException e){e.printStackTrace ();} V<2fPDZ
catch(Exception e){e.printStackTrace ();} w;@25= |
} /rxltF3
JkDPuTXD
#;LMtDaL
//读取保存的下载信息（文件指针位置） xGEmrE<;
private void read_nPos() ^]qV8
{ 2\63&C^
try{ 3zTE4pHzu+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fj-pNl6Gf
int nCount = input.readInt(); kq%gY
nStartPos = new long[nCount]; P%@rH@^Y
nEndPos = new long[nCount]; =Xy`"i{`(
for(int i=0;i<nStartPos.length;i++) Z1$];Q\cX
{ XMEK5Z9Dd
nStartPos = input.readLong(); Q A)9
nEndPos = input.readLong(); {jM<t
} *e3L4 7"G
input.close(); g"]<J&
} n!ZP?]FR
catch(IOException e){e.printStackTrace ();} '"w}gx
catch(Exception e){e.printStackTrace ();} c@9Z&2)
} $FQcDo|[
7<1fKrN?GF
Km9}^*Mo%
private void processErrorCode(int nErrorCode) f']sU/c=
{ w,![;wG
System.err.println("Error Code : " + nErrorCode); P,/13tZ#3
} } }f_
M*O(+EM
IQw %|^
//停止文件下载 *hZ~i{c,7
public void siteStop() ;Lsjh#
{ >{ECyh;
bStop = true; &7($kj
for(int i=0;i<nStartPos.length;i++) r2SJp@f
fileSplitterFetch.splitterStop(); w.D4dv_H
o9i#N
Qb?y@>-[
} /~Zc}o,J
} OgKWgvy
//负责部分文件的抓取 <+\k&W&Y|y
**FileSplitterFetch.java ~TG39*m
*/ ]^; b
package NetFox; B9LSxB
]M~8@K
mNx,L+3
import java.io.*; *9dV/TT~f[
import java.net.*; gp$EXJ=
}$|%/Y
3q#"i&
public class FileSplitterFetch extends Thread { m)@Q_{=6M
Mr=}B6`
Na. nA
String sURL; //File URL KP=D! l&q
long nStartPos; //File Snippet Start Position 6; 5)/q
long nEndPos; //File Snippet End Position n9kd2[s|
int nThreadID; //Thread's ID Gg}5$||^C
boolean bDownOver = false; //Downing is over 7MO
boolean bStop = false; //Stop identical gHi~nEH
FileAccessI fileAccessI = null; //File Access interface m3xz=9Ve
QT1:>k
l5=u3r9WYC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6%ZHP?
{ H_?;h-Y]
this.sURL = sURL; 1UW s_|X!
this.nStartPos = nStart; uX<+hG.n}
this.nEndPos = nEnd; h4XcKv+
nThreadID = id; N 8:"&WM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ezcS[r
} VLh%XoQx[
<`c25ih.4
v9E+(4I9_
public void run() $yDW.pt
{ |.b%rVu
while(nStartPos < nEndPos && !bStop) rDIhpT)a
{ E\R raPkQT
Z!wD~C"D73
<#xrrRhm}
try{ R=\v3m
URL url = new URL(sURL); ]`zjRRd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M8 iEVJ
httpConnection.setRequestProperty("User-Agent","NetFox"); >.J'L5 x$
String sProperty = "bytes="+nStartPos+"-"; n 5~=qQK2
httpConnection.setRequestProperty("RANGE",sProperty); CgVh\4,a
Utility.log(sProperty); <\, &:<
*nYB o\@g
K4j@j}zK9I
InputStream input = httpConnection.getInputStream(); +jq 2pFQ
//logResponseHead(httpConnection); gI)w^7Gi
<K.Bq]
ra]!4Kd'
byte[] b = new byte[1024]; iD%qy/I/
int nRead; cy1\u2x_`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MxY50^}(
{ tCZpfZ@+=
nStartPos += fileAccessI.write(b,0,nRead); 4)c+t"h
//if(nThreadID == 1) IIq"e~"Vs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ')C|`(hs
} LKqRvPnh
cJP'ShnCh
`aO.=:O_
Utility.log("Thread " + nThreadID + " is over!"); <9@&oN+T
bDownOver = true; "0|BoG
//nPos = fileAccessI.write (b,0,nRead); m9#}X_&x
} 5Xwk*@t2a
catch(Exception e){e.printStackTrace ();} 3%XG@OgP
} ^pJ0nY#c
} *Jb_=j*)
|.j^G2x
b\1+kB/8
//打印回应的头信息 n<{aPLQ
public void logResponseHead(HttpURLConnection con) {hxW,mmA
{ M} O[`Fx{W
for(int i=1;;i++) +->\79<#V(
{ Dp!;7e s|
String header=con.getHeaderFieldKey(i); yrO?Np
if(header!=null) Jf_]Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c`-YIz)W
Utility.log(header+" : "+con.getHeaderField(header)); ha_@Yqgh
else PPN q:,
break; L<0=giE
} (.PmDBW
} dF$KrwDK
+d=~LQ}*
7.%f01/i
public void splitterStop() -<O JqB
{ )j\r,9<K+5
bStop = true; 9#u}^t
} {U(Bfe^a,
w]n4KR4
]X*YAPv
} 9^oo-,Su_
GL/ KB
/a%*u6z@
/* 9QX4R<"wUg
**FileAccess.java l#Yx TY
*//文件访问(定位，写) DK)u)?!
package NetFox; Fl<(m
import java.io.*; K~USK?Q%
_=uviMuE
%=BtOM_2
public class FileAccessI implements Serializable{ . /Y&\<
m+H%g"Zj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :#Ty^-"]1
RandomAccessFile oSavedFile; *h2`^Z
long nPos; hPcS, p{%
1c'79YU
n-d:O\]
public FileAccessI() throws IOException NNgK:YibD
{ @Eo4U]-
this("",0); kr#I{gF
} ~fBex_.o*
gTnS[
oK)[p!D?0{
public FileAccessI(String sName,long nPos) throws IOException &%6NQWW
{ Q]/B/
oSavedFile = new RandomAccessFile(sName,"rw"); ,pn)>
this.nPos = nPos; 9MT3T?IS
oSavedFile.seek(nPos); 3#9uEDdE
} RXM}hqeG
^=k{~
A&NqQ V,
public synchronized int write(byte[] b,int nStart,int nLen) 6>s=CiZB
{ pOKeEW<q
int n = -1; 1ADv?+j)A/
try{ ^L ]B5,}-
oSavedFile.write(b,nStart,nLen); N^lAG"Jao[
n = nLen; wajZqC2yg
} 4x(F&0
catch(IOException e) p/N62G
{ +SyUWoM
e.printStackTrace (); b]w[*<f?
} 0:. 6rp
/V#7=,,
#J\s%60pt
return n; dKb ^x^
} Gh'X.?3
n%*tMr9s
XwtAF3oz
} RYH)AS4w'
X>}@EHT
bGu([VB
/* 6i| ~7md,
**SiteInfoBean.java 4Ppop
*/ &;s<dDQK
package NetFox; SAy{YOLtl
s047"Q
LaclC]yLU
public class SiteInfoBean { %uua_&#)
lr0M<5d=p
zXjwnep
private String sSiteURL; //Site's URL AxEc^Cof
private String sFilePath; //Saved File's Path rEmwKZF'
private String sFileName; //Saved File's Name Si]X rub
private int nSplitter; //Count of Splited Downloading File <}cZi4l'
$D}"k!H
G~(&3
public SiteInfoBean() aV#h5s
{//nSplitter的缺省值为5 \ZsP]};*
//default value of nSplitter is 5 2 ^oGwx @
this("","","",5); @C=m?7O98
} L$kgK#T
gX_SKy
]hL:33
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a}dw9wU!:
{ L@?e:*h
sSiteURL= sURL; 12-EDg/1
sFilePath = sPath; }Bi@?Sb
sFileName = sName; B>,A(X&
this.nSplitter = nSpiltter; \qB6TiB/
"Vx6 #u@}
Mb1wYh
} PV(4$I}
5/,Qz>QE[
_-RyHgX
public String getSSiteURL() 8RU.}PD
{ n>S2}y
return sSiteURL; bM^7g
} ~3d*b8
g8'~e{=(
`6}Yqh))
public void setSSiteURL(String value) 5#2jq<D
{ "O``7HA}
sSiteURL = value; v1h.pbz`w
} DL1 +c`d
l|7O)
Wt:~S/l
public String getSFilePath() +<{m45
{ %i595Ij-]
return sFilePath; %jTw
} Cdmy.gx^
:]-$dEu&
KGD'mByt"
public void setSFilePath(String value) [[X+P 0`r
{ %mu>-hac
sFilePath = value; '-.wFB;
} zIm-X,~I$
h1*FPsc
5VZjDg?
public String getSFileName() 7DZTQUb"
{ w&5/Zh[~~L
return sFileName; ntZ~m
} "[.ne)/MC
F 3s?&T)[G
Mt=R*M}D0
public void setSFileName(String value) r>O|L%xpv
{ \OY}GRKt
sFileName = value; /?U!y?t&@
} 2lo:a{}j
%I0}4$
&Sa~/!M
public int getNSplitter() e[8UH=`|
{ <]'|$8&jY
return nSplitter; V)h y0_
} c 6q/X*
#Wk5E2t
z37Z%^
public void setNSplitter(int nCount) UKj`_a6
{ *uU4^E(
nSplitter = nCount; y;QQ| =,
} ^cn@?k((A
} #a'r_K=ch)
@ZG>mP1Vo
Zw24f1iY
/* t\%%d)d9
**Utility.java *:S~C
*/ `2e_ L
package NetFox; L;lk.~V4T
32^#RlSu8
@,e8t BL
public class Utility { }*Zo6{B-
- wWRm
bw5T2wYZ
public Utility() U(Z!J6{c
{ XWXr0>!,?
I=odMw7Hj
7>&1nBh. f
} AqqHD=Yp
yW`e |!
//线程睡眠 R{`gR"*
public static void sleep(int nSecond) =x#&\ui
{ dm& /K 4c
try{ 3HKxYvc C
Thread.sleep(nSecond); WGMb8 /{$P
} s`1^*Dl%+
catch(Exception e) /=/ HB
{ t)'dF*L
e.printStackTrace (); .pW o>`"
} nALnB1
} qRl/Sl#F
4m\([EO
//日志 DJ|BM+
public static void log(String sMsg) OfJd/D
{ jzMg'z/@J
System.err.println(sMsg); `)2[ST
} oLw|uU-|
mw"}8y
+4HlRGH
public static void log(int sMsg) O]bKNA.5
{ &~ y{'zoL
System.err.println(sMsg); *v&*% B
} }H2#H7!H
} l?<q YjI
+`Fb_m)f
P9s_2KOF
/* 'e85s%ru
**TestMethod.java [Xq<EEb
*/ gb(#DbI
package NetFox; Bj8<@~bX:L
Ih3$
6%UY1Q.?
public class TestMethod { \j:AR4
xG w?'\
&+]x;K
public TestMethod() 0$QIfT)
{ ///xx/weblogic60b2_win.exe Uuz?8/w}#
try{ ? oc+ 1e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dk8y>uLr_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qCQu^S' iD
SiteFileFetch fileFetch = new SiteFileFetch(bean); I{EIHD<
fileFetch.start(); ?b"Vj+1:x
} m/{Y]D{2
catch(Exception e){e.printStackTrace ();} ,ex]$fQ'
,jTPg/r
BCBUb
} #fN/LO
L^)qe^%3
C/
public static void main(String[] args) zhjJ>d%w
{ zWtj|%ts
new TestMethod(); 9cz)f\
} zuMO1s
} @.1Qs`pt
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