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)); oS Apa
} pF}WMt
for(int i=0;i<nEndPos.length-1;i++) ><3!J+<?
{ KkD&|&!Q7u
nEndPos = nStartPos[i+1]; 9 Aq\1QC
} rM{V>s:N
nEndPos[nEndPos.length-1] = nFileLength; < r7s,][&
} We?cRb
} z"j]m_mH
GLE"[!s]f
xmBGZ4f%
//启动子线程 \9`76*X6 c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^QTtCt^:
for(int i=0;i<nStartPos.length;i++) Va3/#is'
{ uo[W|Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #f-pkeaeq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dxK3462
nStartPos,nEndPos,i); 5><KTya?=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8q_"aa,`
fileSplitterFetch.start(); )H|cri~D
} O6Mxp-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G"D=ozr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); u;3wg`e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =@y ?Np^A
nEndPos = " + nFileLength); %8$ldNhV
// fileSplitterFetch[nPos.length-1].start(); |cIv&\ x
cPbAR'
=Cg1I\
//等待子线程结束 lXOT>$qR<
//int count = 0; nC(<eL
//是否结束while循环 83g$k 9lG.
boolean breakWhile = false; f S-PM3
J`xCd/G
t5;)<N`
while(!bStop) <tT.m[qg
{ i$JN s)I%
write_nPos(); g`r4f%O
Utility.sleep(500); N977F$Bo
breakWhile = true; 5VjO:>
8~ wP?
v$~$_K
for(int i=0;i<nStartPos.length;i++) t+Au6/Dx?
{ vtF|:*h
if(!fileSplitterFetch.bDownOver) )];Bo.QA
{ am+w<NJ(us
breakWhile = false; $(+#$F<eo+
break; 9>9,
} /X;/}fk
} O b'Br
if(breakWhile) PWk\#dJN&
break; zyP9 n[eZ
;LqpX!Pi f
\-8S"
//count++; s`gfz}/
//if(count>4) SW)jDy
// siteStop(); "/nbcQ*s*E
} i"d&U7Q
r1[c+Hy
<S3s==Cg
System.err.println("文件下载结束！"); K$I`&M(
} (\UpJlW
catch(Exception e){e.printStackTrace ();} 6u>]-K5
} aM+Am,n`@
:}z`4S@b
PUmgcMt
//获得文件长度 1YNw=
public long getFileSize() lokKjs
{ mgMa)yc!dp
int nFileLength = -1; 6bN8}\5
try{ 3JEg3|M(
URL url = new URL(siteInfoBean.getSSiteURL()); \,ne7G21j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 54].p7
httpConnection.setRequestProperty("User-Agent","NetFox"); ]=ADX}
CaC \\5wl
S)?N6sz%
int responseCode=httpConnection.getResponseCode(); ?|~KF:,#}
if(responseCode>=400) G=]ox*BY
{ 1,P\dGmu
processErrorCode(responseCode); .N7<bt@~)
return -2; //-2 represent access is error c h}wXn
} @C%6Wo4l3
[bw1!X3
!yd]~t 5Q
String sHeader; $[Q;{Q
" sC]z}
hpgOsF9Lh
for(int i=1;;i++) yi:}UlO
{ "j&'R#$&d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $6(a6!
//Utility.log(in.readLine()); ex BLj *]
sHeader=httpConnection.getHeaderFieldKey(i); zdw* ?C
if(sHeader!=null) XOLE=zdSp
{ ,Js-'vX
if(sHeader.equals("Content-Length")) hw.>HT|.N
{ |]9L#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~sZ$`t
break; c/igw+L()
} S}a]Bt
} k>\v]&|T`
else JEaTDV_
break; I$MlIz$l v
} Eh)VT{vp
} ``eam8Az_U
catch(IOException e){e.printStackTrace ();} z1]nC]2
catch(Exception e){e.printStackTrace ();} <&#MX
Oet+$ b
KyyVO"
Utility.log(nFileLength); <_ENC>NP
TEh.?
G|[{\
return nFileLength; uT'l.*W6i
} iEZ+Znon
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lx=tOfj8
//保存下载信息（文件指针位置） R :(-"GW'
private void write_nPos() ,wM4X']HR
{ El@*Fo
try{ ;g? |y(xv
output = new DataOutputStream(new FileOutputStream(tmpFile)); jw9v&/-
output.writeInt(nStartPos.length); EEnl'
for(int i=0;i<nStartPos.length;i++) K,I
{ hxK;f
// output.writeLong(nPos); 3fp&iz
output.writeLong(fileSplitterFetch.nStartPos); ~bCA8
output.writeLong(fileSplitterFetch.nEndPos); vsZ?cd
} BV`\6SM~
output.close(); D[#V
} IhBc/.&RL
catch(IOException e){e.printStackTrace ();} o.Rv<a5.L
catch(Exception e){e.printStackTrace ();} YcX\t6VK
} (y 7X1Qc)
*<!q@r<d
)0iN2L]U;
//读取保存的下载信息（文件指针位置） e1LIk1`p
private void read_nPos() BjsT 9?6W/
{ Hj|&P/jY]*
try{ *dw.Ug
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <y] 67:"<v
int nCount = input.readInt(); kI)}7e
nStartPos = new long[nCount]; uT4|43< G
nEndPos = new long[nCount]; `vgaX,F*
for(int i=0;i<nStartPos.length;i++) %ACW"2#(
{ Bskp&NV':
nStartPos = input.readLong(); - ~|Gwr"
nEndPos = input.readLong(); t+iHsCG)>
} w+R7NFq
input.close(); *k}m?;esb
} kuy?n-1g
catch(IOException e){e.printStackTrace ();} wCB*v<*
catch(Exception e){e.printStackTrace ();} lQHF=Jex
} Vv}R S@4U
!T][c~l
hc[ K VLpS
private void processErrorCode(int nErrorCode) /oHCV0!0
{ JEp)8{.bW8
System.err.println("Error Code : " + nErrorCode); ;na%*G`
} 2CO/K_Q
$TXxhd 6
MhD'
//停止文件下载 GDL/5m#
public void siteStop() 5'I+%66?h$
{ hr fF1 >A
bStop = true; su1lv#
for(int i=0;i<nStartPos.length;i++) );7 d_#
fileSplitterFetch.splitterStop(); B#Ybdp ;
B2ln8NF#Q
Yt]`>C[|D
} Q+T#J9Y
} 7H
//负责部分文件的抓取 M?eP1v:<+G
**FileSplitterFetch.java 112WryS
*/ "/aZ*mkjfJ
package NetFox; '" "v7
O8@65URKx
$72eHdy/yl
import java.io.*; bE !SW2:M
import java.net.*; #:gd9os :
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@(sz"
public class FileSplitterFetch extends Thread { G&g;ROgY
gu(:'5cX
j#5a&Z
String sURL; //File URL L1SKOM$
long nStartPos; //File Snippet Start Position ?% 24M\
long nEndPos; //File Snippet End Position >zW2w2O3
int nThreadID; //Thread's ID D$}8GYq
boolean bDownOver = false; //Downing is over k4K. mlIO
boolean bStop = false; //Stop identical ?}cmES kX@
FileAccessI fileAccessI = null; //File Access interface Vke<; k-
F}_b7|^
@Z~YFnEJi
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +#FqC/`l
{ 5~[7|Y
this.sURL = sURL; '? 5-
this.nStartPos = nStart; .uJ J<
this.nEndPos = nEnd; w.?4}'DK
nThreadID = id; 6nW)2LV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X9m^i2tk
} Fc5.?X-
>3uNh:|>/
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public void run() O k`}\NZL
{ s:3[#&PQpN
while(nStartPos < nEndPos && !bStop) 4Hj)Av<O(
{ TJ"-cWpO1
%F 2h C x
hC\ l \y
try{ {<,%_pJR
URL url = new URL(sURL); r:g\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #f2Ot<#-
httpConnection.setRequestProperty("User-Agent","NetFox"); L kK *.
String sProperty = "bytes="+nStartPos+"-"; MGR:IOTa
httpConnection.setRequestProperty("RANGE",sProperty); vE:*{G;Y
Utility.log(sProperty); kB 8^v7o
&: Q'X
f{P1.?a
InputStream input = httpConnection.getInputStream(); W8d-4')|
//logResponseHead(httpConnection); <fUo@]Lv
i>Q!5
h=#w< @
byte[] b = new byte[1024]; TR DQ+Z
int nRead; |MwV4^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lz,M$HG<[
{ TjUwe@&Rw
nStartPos += fileAccessI.write(b,0,nRead); oYqHl1cs
//if(nThreadID == 1) =1IK"BA2?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *ub2dH4/
} m;@q('O
E8PDIjp
%(YQ)=w
Utility.log("Thread " + nThreadID + " is over!"); )2[)11J9t
bDownOver = true; h&0zR#t
//nPos = fileAccessI.write (b,0,nRead); PgkU~68`
} xp^RAVXq`
catch(Exception e){e.printStackTrace ();} e5'I W__
} r:H]`Uo'r
} G2`z?);1b
(/]'e}
y!FO
//打印回应的头信息 FLi'}C
public void logResponseHead(HttpURLConnection con) :G _
{ y]h0c<NP
for(int i=1;;i++) o[ 5dR<
{ 1VJ${\H]
String header=con.getHeaderFieldKey(i); RAW;ze*"
if(header!=null) ER"69zQg|2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z [!"x&H]h
Utility.log(header+" : "+con.getHeaderField(header)); T fLqxioqZ
else [IYVrT&C'
break; V^_A{\GK
} NqD]p{>Y
} `ASDUgx Mq
UoT`/.
Btm,'kBG
public void splitterStop() ^')8-aF .
{ 2) X#&IE
bStop = true; <%)vl P#@
} U6.aoqb%
Ta?J;&<u]/
26j<>>2
} tguB@,O
pD{OB
.QvD603%5
/* "^]gIQc
**FileAccess.java ]_s3<&R
*//文件访问(定位，写) SXL3>-Z E
package NetFox; 2-4N)q
import java.io.*; 4(Lmjue]?
wps/{h,
u&zY>'}zm
public class FileAccessI implements Serializable{ CNNqS^ct
Tz,-~mc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Cut~k"lv
RandomAccessFile oSavedFile; zx#Gm=H4
long nPos; _(m72o0g>>
!5*VBE\
qTuR[(
public FileAccessI() throws IOException kvbZx{s
{ :;%Jm
this("",0); PxKBcx4o`
} +<bj}"
un "I
Q>1BOH1by
public FileAccessI(String sName,long nPos) throws IOException 45yP {+/-Q
{ ;$D,w
oSavedFile = new RandomAccessFile(sName,"rw"); WDc[+Xyw
this.nPos = nPos; '{d_q6,%
oSavedFile.seek(nPos); *V&M5
} s$fM,l:!
+g1>h,K 3
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public synchronized int write(byte[] b,int nStart,int nLen) O,%UNjx9K
{ T}Tv}~!f
int n = -1; dk&F?B{6T
try{ S m(*<H
oSavedFile.write(b,nStart,nLen); G$C2?|V)=
n = nLen; J jAxNviG
} ?_H9>/:.
catch(IOException e) e:G~P u`
{ 24wDnDyh
e.printStackTrace (); <#0i*PM_
} vQ< ~-E
Dw i-iA_q
S*l/ Sa@
return n; h8V*$
} vP{i+s18B
1Ek3^TOv7
_9BL7W $;
} 3,p!Fun:r
W^<AUT
;f%@s1u
/* -VohU-6 |
**SiteInfoBean.java S257+ K9
*/ YKe&Ph.
package NetFox; +?\JQ|
)WvKRp r
NDRDPD
public class SiteInfoBean { 9d1km~
jr6 0;oK+
2P:X_:`~[
private String sSiteURL; //Site's URL >33=0<
private String sFilePath; //Saved File's Path ]]p\1G
private String sFileName; //Saved File's Name ij]UAJ}t
private int nSplitter; //Count of Splited Downloading File Lv+{@)
1(;{w+nM
mc]+j,d
public SiteInfoBean() RZW=z}T+H
{//nSplitter的缺省值为5 1e\cJ{B
//default value of nSplitter is 5 NLZ5 5yo$
this("","","",5); {^oohW -
} :uYZ1O
gb,ZN^3<-
o?ug`m"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J *LPv9)
{ :[@rA;L
sSiteURL= sURL; j+3\I>
sFilePath = sPath; !WXV1S
sFileName = sName; aH;AGbp
this.nSplitter = nSpiltter; .7.1JT#@A7
A^}#
SB%D%Zx6'%
} /BgXY}JC.
nHRsr x
OK4r)
public String getSSiteURL() *Y85evq
{ 38sLyoG=i
return sSiteURL; FW[|Zq;}
} .?:#<=1
+8<$vzB
"PMJh3q
public void setSSiteURL(String value) 'LoWp} f9
{ $j,$O>V
sSiteURL = value; $mK;{9Z
} j f4<LmR
>}wFePl
~>)>hy)
public String getSFilePath() h,y_^cf
{ C'@I!m._i
return sFilePath; -pJ\_u/&%`
} io\t>_
:UT\L2 q=
n-K/dI
public void setSFilePath(String value) v,opyTwG|
{ nt"\FZ*;3
sFilePath = value; xVsI#`<a
} PkFG0
oM1C/=8
w3i74C&0
public String getSFileName() Iep_,o.Sk
{ ?6"U('y>n
return sFileName; 'hu'}F{
} 7 2i&-`&4
[.Fm-$M-
){mqo%{SO
public void setSFileName(String value) {li Q&AZ
{ N MkOx$
sFileName = value; i<$?rB!i<1
} W)Mz1v #s
s/t,6-~EH
)Ko~6.:5H
public int getNSplitter() h:7\S\|8
{ <8~c7kT'
return nSplitter; 1Z?uT[kR
} S -,$ (
IRR b^Q6
uEhPO
public void setNSplitter(int nCount) >B``+Z^2
{ t%,:L.?J#
nSplitter = nCount; D'%M#S0
} 45BpZ~-
} 5{!"}
&*8.%qe;
j"Ew)6j
/* `c^">L
**Utility.java 6*EIhIQ(
*/ W@zxGH$z>
package NetFox; O9<oq
6uUzky
Mcz;`h|EW
public class Utility { Rxr?T-
GBBp1i
Z6-
public Utility() ? 47"$=G
{ cM,g,E}
'ahZ*@kr
fGA#0/_`
} <eS+3,
A|4 3W=
//线程睡眠 Z<=L
public static void sleep(int nSecond) *2.h*y'u
{ p1.3)=T
try{ Gf+X<a
Thread.sleep(nSecond); LOG>x!
} ?I+$KjE+
catch(Exception e) * RX^ z6
{ ^U*1_|Jh
e.printStackTrace (); $tc1te
} p/l">d]+
} L&=r-\.ev
F|'u0JQ)$
//日志 q<^MC/]
public static void log(String sMsg) Chad}zU`
{ 4MzPm~Ct
System.err.println(sMsg); 8}AWU
} zN)).a
,_<|e\>~
C CLc,r>)
public static void log(int sMsg) "j_cI-@6
{ .kkhW8:
System.err.println(sMsg); 1*6xFn
} '.gi@Sr5
} `PI*\t0
CY*GCkH
@CxgoX^
/* H4T~Kv
**TestMethod.java 8<ev5af
*/ Bva2f:)K|
package NetFox; D#`>p
zMO#CZ t
R[*n3 wB
public class TestMethod { L(k`1E
f<|*^+
9x8Vsd
public TestMethod() |QR9#Iv
{ ///xx/weblogic60b2_win.exe a({N}ZDo
try{ ,!PV0(F(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -II03 S1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hM>.xr
SiteFileFetch fileFetch = new SiteFileFetch(bean); Br{(sL0e
fileFetch.start(); =FiO{Aw`N
} {9Ok^O
catch(Exception e){e.printStackTrace ();} k{hNv|:,
V,8Z!.MG
.yD 6$!6
} \}Iq-Je
Fq oh!F
tTubW=H
public static void main(String[] args) ^-|~c`&}B
{ %XZhSmlf
new TestMethod(); pp7 $Q>6
} JY;u<xl
} 8Z"f"
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