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)); H `Fe|6I&
} ,o\vumx
for(int i=0;i<nEndPos.length-1;i++) [9NzvC 9I
{ & D4'hL3
nEndPos = nStartPos[i+1]; * 3mF.^
} +/*,%TdQ4
nEndPos[nEndPos.length-1] = nFileLength; `yJpDGh
} lw0l86^Y
} UbT7
B'B,,Mz
^B~z .F i
//启动子线程 ]cLO-A
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P#bZtWx'<N
for(int i=0;i<nStartPos.length;i++) w$4fS
{ 4vcUHa|4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _!kL7qJ"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m[,! orq
nStartPos,nEndPos,i); Y##ftQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5O<7<OB
fileSplitterFetch.start(); ,-#8/9ts
} >8+:{NW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q-O=Em<*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h^eaV,x>=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a,IE;5kG
nEndPos = " + nFileLength); PJLSDIeN
// fileSplitterFetch[nPos.length-1].start(); Zoh[tO
^6`"f
EOWLGleD1
//等待子线程结束 ,cD(s(6+
//int count = 0; >.N?y@
//是否结束while循环 q"4{GCavN
boolean breakWhile = false; gnF]m0LR
p=_K P9
oF[l<OY4
while(!bStop) ys|a ^VnN
{ y}dop1zp
write_nPos(); 4`Qu+&4J
Utility.sleep(500); CEjMHP$=
breakWhile = true; Mq;m+{B
C5GO?X2
hs< )<
for(int i=0;i<nStartPos.length;i++) ,,vl+Z<&
{ n!e4"|4~z
if(!fileSplitterFetch.bDownOver) )OxcJPo
{ uc4#giCD
breakWhile = false; _Vr>/f
break; Y8YNRyc=
} }DiMt4!ZC!
} /ghXI"ChI
if(breakWhile) H7!j5^
break; wd&Tf R4!
mb_*FJB-_
nS'hdeoW
//count++; gOaL4tu
//if(count>4) LRl2@&z<
// siteStop(); 2;N)>[3*J
} jA9&hbQuL
HC4qP9Gs
T@0\z1,~S
System.err.println("文件下载结束！"); MBZ/Pzl~
} ]/>(C76
catch(Exception e){e.printStackTrace ();} DY| s|:d
} AB92R/
SJ4[n.tPI
5{?J5
//获得文件长度 2)oT\m
public long getFileSize() NJ\ID=3l
{ /~RY{ c@#L
int nFileLength = -1; !Wn^B|
try{ i!5zHn
URL url = new URL(siteInfoBean.getSSiteURL()); \!D<u'n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ghtvAG
httpConnection.setRequestProperty("User-Agent","NetFox"); 6Ap-J~4
{akSK
.URCuB\{
int responseCode=httpConnection.getResponseCode(); xx[XwN;
if(responseCode>=400) ~wtl\-cY
{ @,btQ_'X
processErrorCode(responseCode); mOm_a9ML
return -2; //-2 represent access is error ?J[m)Uo/K
} 1yHlBeEC
)nncCUW
^lADq']
String sHeader; wQ!C9Gp3e
yb{ud
k0[b4cr`
for(int i=1;;i++) h0i/ v
{ /1A3 Sw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !kAjne8]d
//Utility.log(in.readLine()); -.XICKz
sHeader=httpConnection.getHeaderFieldKey(i); )?es3Ehqq
if(sHeader!=null) !$}:4}56F
{ ,+LX.f&/8!
if(sHeader.equals("Content-Length")) N$cm;G=]
{ <:(pnw*L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C%#%_ "N
break; _Z9HOl@
} |%p;4b
} tb#9TF
else ollJ#i9
break; `XT8}9z!
} 6}b1*xQ
} J/OG\}
catch(IOException e){e.printStackTrace ();} >ucVrLm,X
catch(Exception e){e.printStackTrace ();} R<* c
7sgK+ ip
gzV&S5A{_
Utility.log(nFileLength); t(d$v_*y51
,# i@jB
H> Y0R
return nFileLength; G3Z>,"w;=
} yiourR)H<
F?APDGAN
}bkQr)us
//保存下载信息（文件指针位置） h!@t8R
private void write_nPos() mI$<+S1!
{ r .&<~x
try{ c4\Nuy
output = new DataOutputStream(new FileOutputStream(tmpFile)); aHhr_.>X
output.writeInt(nStartPos.length); kfb*|
for(int i=0;i<nStartPos.length;i++) vIMLUL0
{ }MW7,F
// output.writeLong(nPos); ->H4!FS
output.writeLong(fileSplitterFetch.nStartPos); *?l-:bc]
output.writeLong(fileSplitterFetch.nEndPos); kK62yz,
} 3vcKK;qCB
output.close(); Hj\iI p
} )R~l@QBN
catch(IOException e){e.printStackTrace ();} |+-D@22y
catch(Exception e){e.printStackTrace ();} )Id.yv}_
} moop.}O<
2b&&3u8
3izGMH_`
//读取保存的下载信息（文件指针位置） `]u!4pP"
private void read_nPos() |8m2i1XG
{ ET2^1X#j
try{ T6Oah:50EM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^0x0 rY
int nCount = input.readInt(); NZ{)&ObBRt
nStartPos = new long[nCount]; d9qA\ [
nEndPos = new long[nCount]; +mgm39
for(int i=0;i<nStartPos.length;i++) ff{L=uj
{ e-@.+f2CC
nStartPos = input.readLong(); vJ&g3ky
nEndPos = input.readLong(); aAT!$0H
} [5"F=tT7WP
input.close(); AlVBhR`
} *_qLLJg
catch(IOException e){e.printStackTrace ();} < 2mbR
catch(Exception e){e.printStackTrace ();} 2:8p>^g=
} 2#y-3y<G
G(Ky7SZ
.+.'TY--
private void processErrorCode(int nErrorCode) 5LYzX+a)
{ p?6`mH
System.err.println("Error Code : " + nErrorCode); {S$]I)tV
} btG+Ak+K*
~uUN\qx52
UG~/
//停止文件下载 ntZl(]l
public void siteStop() ^!FLi7X
{ t[|aM-F&>
bStop = true; 4?u<i=i
for(int i=0;i<nStartPos.length;i++) 0t^Tm0RzH
fileSplitterFetch.splitterStop(); ge[hAI2I
TF[8r[93
\LEUreTn
} flXDGoW
} W }"n*
//负责部分文件的抓取 -Uj3?W
**FileSplitterFetch.java NB.s2I7
*/ qhQeQ
package NetFox; \46 'j.
<rbzsn"a
"<=HmE-;
import java.io.*; ]Jum(1Bo
import java.net.*; 2 {I(A2
Z`jSpgWR
!5VT[w 1
public class FileSplitterFetch extends Thread { jqJ't)N
7jzd I!
6");NHE
String sURL; //File URL d95 $w8>
long nStartPos; //File Snippet Start Position -|WQs'%O
long nEndPos; //File Snippet End Position "oLY";0(=
int nThreadID; //Thread's ID "0sk(kT
boolean bDownOver = false; //Downing is over cq0#~20
boolean bStop = false; //Stop identical ,?KN;~t#vz
FileAccessI fileAccessI = null; //File Access interface ~2L]K4Z^
mh:eUFe
SKdh!*G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M\!z='Fi
{ tYzpL
this.sURL = sURL; 6}"t;4@$x
this.nStartPos = nStart; ]7/6u.G7R
this.nEndPos = nEnd; 6%\&m|S
nThreadID = id; z:JQ3D7/we
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "74Rn"d5
} 6^#@y|.
RK\$>KFE
JIh:IR(ta
public void run() }M|,Z'@*
{ *,y .%`o
while(nStartPos < nEndPos && !bStop) i!7|YAu
{ hTS?+l
KwxO%/-}S
Y$K[@_dv=
try{ Og E<bw
URL url = new URL(sURL); ^,sKj-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gQ;1SY!
httpConnection.setRequestProperty("User-Agent","NetFox"); Ef"M e(
String sProperty = "bytes="+nStartPos+"-"; fZNWJo# `.
httpConnection.setRequestProperty("RANGE",sProperty); o"Mhwh
Utility.log(sProperty); 0~GtK8^B
< /\y<]b
RS9mAeX4h
InputStream input = httpConnection.getInputStream(); NB#-W4NA
//logResponseHead(httpConnection); -d8U Hc
rL3 f%L
K)_DaTmi)
byte[] b = new byte[1024]; cms9]
int nRead; SMIr@*R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KOYcT'J@vR
{ <xO" E%t
nStartPos += fileAccessI.write(b,0,nRead); #57D10j
//if(nThreadID == 1) a%NSL6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *)0-N!N#)
} +S C;@'
vq;_x
g|V md
Utility.log("Thread " + nThreadID + " is over!"); IWs)n1D*]
bDownOver = true; T$vDw|KSVP
//nPos = fileAccessI.write (b,0,nRead); ^R;rrn{^
} am(jmf::
catch(Exception e){e.printStackTrace ();} k*"FMJG_
} )4CF*>*6V
} $5v:z
{wy#HYhv
8D5v'[j-
//打印回应的头信息 bS"zp6Di
public void logResponseHead(HttpURLConnection con) 60Szn]z'8[
{ Bq*aP*jv
for(int i=1;;i++) LqcHsUFj
{ ,HHCgN
String header=con.getHeaderFieldKey(i); na-mh E,H
if(header!=null) ,3p$Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Hy| X>Z
Utility.log(header+" : "+con.getHeaderField(header)); 9f7T.}HM
else *r|)@K|
break; J%SuiT$L&Y
} EI!e0V1!
} ai@hQJ*
\Zbi`;m?
Im<(
public void splitterStop() {(j1#9+9
{ p0Ra`*f
bStop = true; VyWPg7}e
} Jh!'"7
%K7wScz7
R^ &nBwp
} 4 /Q4sE~<
*p=a-s5-
>cYYr@S
/* TF7~eyLg
**FileAccess.java Tn"/EO^N
*//文件访问(定位，写) ^mZeAW
package NetFox; c D0-g=&
import java.io.*; 3,[#%}1(S
7,:$, bL
j]5mzz~
public class FileAccessI implements Serializable{ "GY/2;
Q( g&/O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @24)*d^1
RandomAccessFile oSavedFile; Z(0sMOaX
long nPos; P{ HYZg
wOU\&u|
{j!+\neL
public FileAccessI() throws IOException ~4'AnoD1w
{ j|X>:!4r
this("",0); yK"T5^o
} >J,y1jzJ
OD~B2MpM>
9#iv|X
public FileAccessI(String sName,long nPos) throws IOException gtVnn]Jh
{ %{*)-_M
oSavedFile = new RandomAccessFile(sName,"rw"); x-%4-)
this.nPos = nPos; Kg>ehn4S@
oSavedFile.seek(nPos); f&ri=VJY\T
} 'j27.Ry.
"2 "gTS
P<s0f:".
public synchronized int write(byte[] b,int nStart,int nLen) ;I@@PUnR
{ -H-:b7
int n = -1; h =E)5&Z
try{ (#?k|e"Y"`
oSavedFile.write(b,nStart,nLen); f9FEH7S68
n = nLen; bxR6@
} v62O+{
catch(IOException e) BfUM+RC%5
{ (eEs0
e.printStackTrace (); #ssSs]zl
} >xB[k-C4
_ 0g\g~[
yNU.<d 5
return n; x_VD9
} eF=cMC
?=#vp /
:Y)jf
} ;FfDi*S7
4SDUTRoa
Z\. n6
/* Nt'6Y;m!
**SiteInfoBean.java ":!7R<t
*/ 'ugc=-0pd
package NetFox; ;:DDz
oQ:.pq{T
h}$g}f%$+
public class SiteInfoBean { pEp`Z,p
Ef~Ar@4fA
|S0nR<x-M
private String sSiteURL; //Site's URL qr<RMs
private String sFilePath; //Saved File's Path 0+dc
private String sFileName; //Saved File's Name K*id 1YY
private int nSplitter; //Count of Splited Downloading File 2>+(OL4l
b<bj5m4fz>
dgp1B\
public SiteInfoBean() d.3cd40Q
{//nSplitter的缺省值为5 T j(MIFi|5
//default value of nSplitter is 5 "\`>Ll
this("","","",5); Wb{0UkApJ
} }p|S3/G?$!
J1UG},-h
0ub0[A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) UI%Z`.&
{ ATzFs]~K;
sSiteURL= sURL; *'to#_n&W
sFilePath = sPath; =8V 9E
sFileName = sName; l' mdj!{&
this.nSplitter = nSpiltter; Uu_Es{@
j[Q9_0R~lR
j/p1/sJ[y
} h"3Mj*s
DmtCEKa
\`U=pZJ
public String getSSiteURL() e%_J O7
{ 'B\7P*L"p
return sSiteURL; PK).)5sW
} %5$)w;p.$'
sXaudT
"K c/Cs2[
public void setSSiteURL(String value) Rl{e<>O\^
{ v8l3{qq
sSiteURL = value; B? Z_~Bf&
} Lm3~< vP1e
.L@gq/x)
1Eh6ti
public String getSFilePath() \@B'f
{ pv]2"|]V)
return sFilePath; 6^e}^~|
} WCD)yTg:ES
_J"fgxW
.]w=+~h
public void setSFilePath(String value) Qg]+&8!*
{ Mz6PH)e;
sFilePath = value; %jJ|4\
} ey@ccc*sZ9
8I[=iU7]l
SA?lDRF
public String getSFileName() U8zCV*ag
{ b4&l=^:e=
return sFileName; Nsn~mY%
} i_(6}Y&
PW_"JZ
H1.ktG
public void setSFileName(String value) i__f%j`!W
{ MfZamu5+F
sFileName = value; 0bG#'.-
} Ao+6^z_
}qT{" *SC
\`;1[m
public int getNSplitter() Rt>mAU$}
{ "`NAg
return nSplitter; xLSf /8e
} K7R!E,oPg
Ae\:{[c_D
h~lps?.#b
public void setNSplitter(int nCount) wk#cJ`wG;
{ H<3:1*E
nSplitter = nCount; U@9v(TfV
} lAR1gHhJ
} 22'Ra[
}9kn;rb$g
NvC @
/* 1-$+@Xl
**Utility.java EU7nS3K)O~
*/ t$ 97[ay
package NetFox; tA]u=-_h
0avtfQ +f
{n&GZG"f
public class Utility { OLo?=1&;;
_6!iv
fA"c9(>m%]
public Utility() d_!}9
{ [dFe-2u ,$
Zv2]X-
AZf69z
} RxS{
hBaF^AWW
//线程睡眠 ,`PYU[
public static void sleep(int nSecond) h^v#?3.@
{ \u04m}h]
try{ =KAN|5yn
Thread.sleep(nSecond); F"cZ$TL]
} ;66{S'*[
catch(Exception e) BNe>Lko
{ \r9E6LLX'
e.printStackTrace (); I:w+lchAMe
} -g:i'e
} "_2;+@+
EEMRy
//日志 }u8g7Nj
public static void log(String sMsg) q6b&b^r+H
{ }u1h6rd `
System.err.println(sMsg); D^a(|L3;
} QyY<Zi;6
YI;MS:Qj
;VEKrVD
public static void log(int sMsg) =f23lA
{ :sw@1
System.err.println(sMsg); ta<8~n^?
} _2)QL
} cj^hwtx
oIQ$98M
Q,Y^9g"B`~
/* 3bJ|L3G
**TestMethod.java p>f?Rw_
*/ F>5b[q6~4
package NetFox; fQwLx
lon9oraF'
d^v.tYM$N
public class TestMethod { fz?woVn
s}yN_D+V
kZ]pV=\Y*
public TestMethod() fW[RCd
{ ///xx/weblogic60b2_win.exe FUZuS!sJ
try{ |DPq~l(d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $~j9{*]5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N7KG_o%
SiteFileFetch fileFetch = new SiteFileFetch(bean); #_|O93HN'
fileFetch.start(); I[?bM-
} GctV
catch(Exception e){e.printStackTrace ();} lA;qFXaN>
E$&bl
UI'fzlB
} -3y
9g'6zB
0P{8s
public static void main(String[] args) Rlm28
{ U_.}V
new TestMethod(); [Q\(kd*4
} 3xKgj5M
} FQE(qltf,
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