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)); CgKFI
} .J\i!
for(int i=0;i<nEndPos.length-1;i++) ]~4*ak=)5\
{ Tfw5i,{
nEndPos = nStartPos[i+1]; cQ(,M
} .cB>ab&
nEndPos[nEndPos.length-1] = nFileLength; S%o6cl=
} scZ&}Ni
} <%S[6*6U
o^Qy71Uj
'25zb+-
//启动子线程 <=@6UPsn2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Xw&vi\*m
for(int i=0;i<nStartPos.length;i++) QsyM[;\j:
{ $>hH{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ORFi0gFbA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mX GW+
nStartPos,nEndPos,i); :a_MT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yDAvl+
fileSplitterFetch.start(); 6NGQU%Hd
} C@ "l"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )TwA?kj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yXBWu=w3`O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RSIhZYA
nEndPos = " + nFileLength); tD6ukK1x
// fileSplitterFetch[nPos.length-1].start(); $"fO/8Ex
8r48+_y3u
pf#~|n#t
//等待子线程结束 s"(F({J
//int count = 0; D'Uv7Mis
//是否结束while循环 |v:fP;zc
boolean breakWhile = false; 4Q~++PKBe
a@m 64l)
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while(!bStop) bM"d$tl$?'
{ =:m6ge@C&H
write_nPos(); ai;-_M+$
Utility.sleep(500); 3q.HZfN~
breakWhile = true; Y/qs\c+
\{ff7_mLo
CykvTV Q
for(int i=0;i<nStartPos.length;i++) T*](oA@
{ 7mnZ,gpb
if(!fileSplitterFetch.bDownOver) #ib?6=sPC
{ S(G&{KG
breakWhile = false; G1ED=N_#
break; jk1mP6'P|
} mw~$;64;a
} a~F\2`Q
if(breakWhile) XRXQ 7\n
break; K.42 VM)F
[k60=$y
+4V"&S|&
//count++; c? >;UzM
//if(count>4) d%#5roR4<
// siteStop(); %APeQy"6#^
} Em/? 4&
p`}G"DM
'y|p)r"
System.err.println("文件下载结束！"); !XT2'6nu
} B X Et]+Q
catch(Exception e){e.printStackTrace ();} Mi7LyIu
} 2]+f<Z[/
!~te&ccPE
.{"wliC2
//获得文件长度 E*VOyH2[
public long getFileSize() _o?[0E
{ j~#v*qmDU
int nFileLength = -1; h:4F?'W
try{ wPr!.:MF
URL url = new URL(siteInfoBean.getSSiteURL()); 5N$O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4td9=dNA+l
httpConnection.setRequestProperty("User-Agent","NetFox"); ~U1M-<IX
i(0%cNP7
7a4h7/
int responseCode=httpConnection.getResponseCode(); sg4TX?I
if(responseCode>=400) $8fJDN
{ ~-#8j3 J;
processErrorCode(responseCode); BZk0B?
return -2; //-2 represent access is error 8Wx7%@^O
} !%>(O@~"|
%!OA/7XbG
$q0i=l&$&
String sHeader; AV;x'H7G
NH!x6p]n
K#[z5
for(int i=1;;i++) uw{K&Hxw
{ B=|m._OL]n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Jv59zI
//Utility.log(in.readLine()); zUz j F
sHeader=httpConnection.getHeaderFieldKey(i); %dq|)r
if(sHeader!=null) *q0vp^?
{ |I s"ov
if(sHeader.equals("Content-Length")) +H "j-:E@t
{ C |P(,Xp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \'>d.'d
break; 7-4S'rq+
} *iXaQuT
} DUvF
else SAokW,
break; Tr"Bz!
} EsjZ;D,c(
} #~`d ;MC
catch(IOException e){e.printStackTrace ();} ejlau#8"
catch(Exception e){e.printStackTrace ();} ~~{+?v6B]
z{A~d
@K}Bll.E
Utility.log(nFileLength); mZ#h p}\.
!.[H!-V.
_PGS"O?j
return nFileLength; sQ8kLS_q8
} mC./,a[
b^WF R
kB]*2o9-3
//保存下载信息（文件指针位置） Q =4~uz|
private void write_nPos() -5MQ/ujQ
{ |^ J5YwCf
try{ BH2JH>'X
output = new DataOutputStream(new FileOutputStream(tmpFile)); Sj@VOW
output.writeInt(nStartPos.length); 2;`WI:nt
for(int i=0;i<nStartPos.length;i++) DQ%(X&k
{ 5@`dKFB5
// output.writeLong(nPos); $Sc;
output.writeLong(fileSplitterFetch.nStartPos); *m:'~\[u
output.writeLong(fileSplitterFetch.nEndPos); `W'S'?$
} pu Z0_1uN
output.close(); :zsMkdU
} `f\+aD'u
catch(IOException e){e.printStackTrace ();} ,*g.?q@W2
catch(Exception e){e.printStackTrace ();} ant#bDb/
} d%Nx/DS)
i} ?\K>BWq
lcEUK
//读取保存的下载信息（文件指针位置） 7 MG<!U
private void read_nPos() 4[n[Ch=lu
{ +=#@1k~
try{ %(izKJl q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KqFiS9 N5
int nCount = input.readInt(); i#(+Kxr]>
nStartPos = new long[nCount]; Y(h(Z
nEndPos = new long[nCount]; 30Udba+{]p
for(int i=0;i<nStartPos.length;i++) cb%ML1c
{ :?H1h8wbCt
nStartPos = input.readLong(); gCv[AIE_m
nEndPos = input.readLong(); \x=!'
} >W^)1E,Qh
input.close(); EL;OYW(
} ]vZ}4Xno
catch(IOException e){e.printStackTrace ();} M nDaag
catch(Exception e){e.printStackTrace ();} "rR$2`v"
} BD&AtOj[,
Fz^5cxmw
V5S6?V\
private void processErrorCode(int nErrorCode) !b'!7p
{ (]sk3 A
System.err.println("Error Code : " + nErrorCode); R/kfbV-b
} m";?B1%x
'Jl3%axR
C&&33L
//停止文件下载 /[UuHU5*R
public void siteStop() #gRtCoew
{ .MW/XnCYs4
bStop = true; ]QmY`pTB`
for(int i=0;i<nStartPos.length;i++) 1owe'7\J
fileSplitterFetch.splitterStop(); Ct386j><
884-\M"h
ms/Q-
} %^(} fu
} >^Y)@J
//负责部分文件的抓取 h#]LXs
**FileSplitterFetch.java \\$wg
*/ K"g`,G6S
package NetFox; vKTCS
d?>pcT)G_
. /~#
import java.io.*; qaEWK0
import java.net.*; )/uCdSDIc
2[5z6oG
trM)&aQto
public class FileSplitterFetch extends Thread { a\Dw*h?b~
0m'tPFQ|
^LAdN8Cbb
String sURL; //File URL 4/E>k <MA
long nStartPos; //File Snippet Start Position -k}&{v
long nEndPos; //File Snippet End Position -SKcS#IF
int nThreadID; //Thread's ID -|`E'b81
boolean bDownOver = false; //Downing is over f4&k48Ds
boolean bStop = false; //Stop identical },vVc/
FileAccessI fileAccessI = null; //File Access interface P*9L3R*=N
#4ii!ev
QS2~}{v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]hlYmT
{ A?Gk8
this.sURL = sURL; S")*~)N@
this.nStartPos = nStart; YveNsn
this.nEndPos = nEnd; 'cvc\=p
nThreadID = id; 6|ENDd[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l&6+ykQ
} tk'3Q1L
}d16xp
0A.9<&Lod
public void run() o3>D~9
{ CUa`#
while(nStartPos < nEndPos && !bStop) 6cbIs_g
{ a~O](/+p;
E]%&)3O[
fg~9{1B
try{ 02~GT_)$^
URL url = new URL(sURL); N="H 06t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +y|H#(wBP
httpConnection.setRequestProperty("User-Agent","NetFox"); cK6IyJx-
String sProperty = "bytes="+nStartPos+"-"; 1iIag}?p
httpConnection.setRequestProperty("RANGE",sProperty); Q)l~?Fx
Utility.log(sProperty); 6Z68n
d> L*2 g
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InputStream input = httpConnection.getInputStream(); ~{BR~\D
//logResponseHead(httpConnection); s&Ml1A:
<" F|K!Tz
Ol1P
byte[] b = new byte[1024]; >}>cJh6
int nRead; LOlj8T8Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #;Z+X)
{ _:.'\d(
nStartPos += fileAccessI.write(b,0,nRead); (S k+nD
//if(nThreadID == 1) _-bEnF+/0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jGKasI`
} $Y_v X 2
j[\aGS7u
s14;\
Utility.log("Thread " + nThreadID + " is over!"); XyE%<]
bDownOver = true; qjVhBu7A
//nPos = fileAccessI.write (b,0,nRead); iV8O<en&i
} <[<]+r&*
catch(Exception e){e.printStackTrace ();} pPtw(5bH
} +*P;Vb6D
} yB,{:kq7D
:gacP?
/2AeJH\-
//打印回应的头信息 Q>[GD(8k
public void logResponseHead(HttpURLConnection con) %2`geN<
{ _0=$ 2Y^
for(int i=1;;i++) L4H5#?'
{ 8cv[|`<
String header=con.getHeaderFieldKey(i); a0[Mx 4
if(header!=null) %!QY:[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hNGD`"U
Utility.log(header+" : "+con.getHeaderField(header)); ;mLbgiqQ J
else +5IC-=ZB
break; _!C'oG6s?
} Zlf) dDn
} LFV',1+
%<Te&6NU'
QX&1BKqWn
public void splitterStop() coFQu ;i
{ osW"b"_f
bStop = true; wf=M| #}_
} 3rQ;}<*M
g7nqe~`{
6qzyeli
} 6I,4 6 XZ-
iH[ .u{h
#ZvDf5A
/* T*8rR"
**FileAccess.java Uv"O'Z
*//文件访问(定位，写) @8xa"Dc
package NetFox; XZ!^kftyW
import java.io.*; ,zU7UL^I
WnZn$N.
8ECBi(
public class FileAccessI implements Serializable{ !JC!GS"M5
Mk$Pt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %K|+4ZY3
RandomAccessFile oSavedFile; vaOCH*}h
long nPos; 5fVm392+
#K_E/~
zM*PN|/%sH
public FileAccessI() throws IOException CH3bpZv
{ h|S6LgB
this("",0); _/ Uer}
} [j^c&}0
_ BUD~'Q5
L:3
public FileAccessI(String sName,long nPos) throws IOException E3<~C(APW
{ FeAMt
oSavedFile = new RandomAccessFile(sName,"rw"); =hse2f
this.nPos = nPos; KOM]7%ys1H
oSavedFile.seek(nPos); Fi*j}4F1
} H(k-jAO,
Msea kF
G'qGsKf\
public synchronized int write(byte[] b,int nStart,int nLen) ;]+p>p-#
{ V]I+>Zn| 7
int n = -1; ??tNMr5{[
try{ K$(LiP
oSavedFile.write(b,nStart,nLen); E A8>{}Z*
n = nLen; L-v-KO6
} k%S;N{Qh@
catch(IOException e) K4>nBvZ?v
{ >4N=P0=
e.printStackTrace (); o$FYCz n
} yC<[LH
%SSBXWP
ubvXpK:.
return n; C-6m[W8S
} y~AF|Dk=
'E#;`}&Ah
q&`>&k
} O=LiCSNEV
!tL&Ktoj
ehCZhi~
/* uk)6%
**SiteInfoBean.java !O-9W=NJ
*/ PC3-X['[
package NetFox; -6./bB g
5o dtYI%L
n:P5m9T
public class SiteInfoBean { jLLZZPBK
+,BJ4``*k
n-Qpg
private String sSiteURL; //Site's URL 5QoU&Hv
private String sFilePath; //Saved File's Path 4$=ATa;x-
private String sFileName; //Saved File's Name bBC!fh!L"
private int nSplitter; //Count of Splited Downloading File c6 tB9b
D^%DYp
P)$q
public SiteInfoBean() !e"TWO*X
{//nSplitter的缺省值为5 QTNE.n<?
//default value of nSplitter is 5 aC#8%Spj
this("","","",5); DKGZm<G>
} 9:l@8^_o
^%:syg_RM[
==z,vxr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;:)?@IuSy
{ &InMI#0mV
sSiteURL= sURL; 9 yE
sFilePath = sPath; gU^2;C
sFileName = sName; )]?"H
this.nSplitter = nSpiltter; |{8eoF
LBkAi(0rd
Vg+jF!\7
} iKu~o.yy
4Nx]*\\
[x.DwU%S
public String getSSiteURL() &oyj8
{ sb7~sa&-
return sSiteURL; o/U"'FP
} ~YX!49XfHh
&xGcxFd
Q41eYzAi
public void setSSiteURL(String value) a &89K
{ &74*CO9B9
sSiteURL = value; qU) pBA
} Q]u*Oels
u9 yXHf
9W[ ~c"Ku
public String getSFilePath() Td`0;R'<}c
{ bz=B&YR
return sFilePath; 8+irul{H_
} = +=k(*
vV?=r5j
)Z2l*fV
public void setSFilePath(String value) dgIEc]#pH
{ 0y"Ra%Y
sFilePath = value; u=5~^ 9
} %Z"I=;=nxI
#CaT0#v
y_=},a
public String getSFileName() 6tBh`nYB=
{ ^?5[M^
return sFileName; t*&O*T+fgy
} >**7ck
A+N%A]2
|Ir&C[QS{y
public void setSFileName(String value) laQM*FLg
{ ;U^7]JO;
sFileName = value; T%\f$jh6
} 4l6+8/Y
@AgV7#
7:h8b/9
public int getNSplitter() QF7iU@%-
{ F^v <z)x
return nSplitter; NG2@.hP:uU
} 2 P=c1;
"[*W=6m0
z}" Xt=G?
public void setNSplitter(int nCount) &mM[q'V
{ 2[Ja|W\If
nSplitter = nCount; km]RrjRp
} k3/V$*i,1b
} z8ox#+l
GV5hmDzRs
KV!!D{VS`@
/* whzV7RT
**Utility.java Z|z+[V}[
*/ `qjiC>9
package NetFox; pV3o\bk!
FE`:1
Vko1{$}t
public class Utility { W* XG9
d +]Gw
8mCL3F
public Utility() !i|]OnJY
{ ZS-O,[
5F8sigr/h
bOi`JJ^
} {!B^nCSL
aK%i=6j!
//线程睡眠 xlqh,?'>W
public static void sleep(int nSecond) p.gaw16}>
{ gX}(6RP_!
try{ -L&FguoVB
Thread.sleep(nSecond); U-P\F-
} gUoL8~
catch(Exception e) 7,sslf2%K
{ FE)L?
e.printStackTrace (); (5SN=6O
} G|Du/XYh
} *o/Q#
0<{+M`G/
//日志 ]yxRaW9f
public static void log(String sMsg) `g;`yJX<
{ H)s$0Xd
System.err.println(sMsg); L y!!+UM\
} 8H>: C(h
_pXy}D
Z|FWQ8gZ4m
public static void log(int sMsg) 8TK&i,
{ u |hT1l
System.err.println(sMsg); Ol,Tw=?
} qc*z`Wz:
} SWX;sM
9`/\|t|V
^<0azza/(
/* Lh%>> Ht{
**TestMethod.java }*2q7K2bj
*/ piRP2Lbm*
package NetFox; 2BU%4IG
g,5r)FU`
1k5o?'3&
public class TestMethod { YGBVGpE9
3w=OvafT:
7*e7P[LQU
public TestMethod() Ip/_uDi+!Z
{ ///xx/weblogic60b2_win.exe !H`! KBW
try{ O\64)V 0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,cR=W|6cQm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y7{9C*>
SiteFileFetch fileFetch = new SiteFileFetch(bean); R"S,&
fileFetch.start(); S C8r.
} s V70a3#
catch(Exception e){e.printStackTrace ();} 7|A9
HWFI6N
-q9`Btz
} 2=3pV!)4}
4s?x 8oAy
69U[kW&
public static void main(String[] args) yq{k:)
{ `%lgT+~T
new TestMethod(); RCED K\*m
} L:HJ:
} 0jY#,t?>
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