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)); )/Y~6A9>
} X>3^a'2,E
for(int i=0;i<nEndPos.length-1;i++) UxqWnHH.`
{ Q1V2pP+=@
nEndPos = nStartPos[i+1]; /~hbOs/ L
} 7'.s7& '7
nEndPos[nEndPos.length-1] = nFileLength; %C*^:\y
} gGbI3^r#
} }98-5'u.X
SMO*({/
$KQ,}I
//启动子线程 Auac>')&Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #93}E Y
for(int i=0;i<nStartPos.length;i++) i^/54
{ K`(#K#n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^KH%mSX>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u4"r>e6_B
nStartPos,nEndPos,i); <Jwo?[a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L8P36]>
fileSplitterFetch.start(); #v/ry)2Y=
} l>Av5g)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wRbw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .TN2s\:]jw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l2/@<0P
nEndPos = " + nFileLength); jgRCs.6
// fileSplitterFetch[nPos.length-1].start(); VO-784I
qZsnd7o{l.
VkXn8J
//等待子线程结束 F6&P~H
//int count = 0; p7[(z
//是否结束while循环 =]KIkS3
boolean breakWhile = false; e^frVEV
[=~!w_
cjY@Ot*i$
while(!bStop) 4A o{M
{ ND,`QjmZ
write_nPos(); 9[{sEg=C$e
Utility.sleep(500); 3^~Zj95M
breakWhile = true; Czh8zB+r
"::9aYd!
~d+O/:=K_
for(int i=0;i<nStartPos.length;i++) .0 X$rX=
{ Q X):T#^V
if(!fileSplitterFetch.bDownOver) V.j#E1P
{ FO^24p
breakWhile = false; ?*o;o?5s^
break; qw0~*0}
} fLM.kCD?u
} +$~8)95<B
if(breakWhile) |_I[1%&`N
break; |Gc&1*$
npj5U/
RpeBm#E2
//count++; O3xz|&xY&
//if(count>4) m)k-uWc$C
// siteStop(); sL mW\\kA>
} bL MkPty
$Sw,hb
T#N80BH[
System.err.println("文件下载结束！"); UzJ!Y/5
} ASq`)Rz
catch(Exception e){e.printStackTrace ();} /&6Q)
} !PI0oh
pXNtN5@FQ
J[o${^
//获得文件长度 `D"1 gD}{A
public long getFileSize() ](n69XX_
{ !ABLd|tP
int nFileLength = -1; PHQcstW
try{ dcP88!#5-
URL url = new URL(siteInfoBean.getSSiteURL()); w= B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cf&C|U
httpConnection.setRequestProperty("User-Agent","NetFox"); <G}m#
7YD\ !2b
C=s((q*
int responseCode=httpConnection.getResponseCode(); i8eA_Q
if(responseCode>=400) !|(Ao"]
{ ULck
processErrorCode(responseCode); oE5;|x3
return -2; //-2 represent access is error 6Ok,_ !
} CQjV!d0j
30BR0C
8(uw0~GO
String sHeader; K)N)IZ1q
_-(z@
/O_0=MLp
for(int i=1;;i++) +>^[W~[2
{ )2toL5Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *.,8,e8Vq
//Utility.log(in.readLine()); Es:5yX!
sHeader=httpConnection.getHeaderFieldKey(i); ~Ji>[#W K
if(sHeader!=null) WQTendS
{ @21u I{
if(sHeader.equals("Content-Length")) L*IU0Jy>
{ +Bn?-{h=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KG-UW
break; k=FcPF"
} pBvo M={2!
} W*3o|x
else Ipg\9*c`
break; '%:5axg?]
} z(jU|va{_1
} 9M;I$_U`vj
catch(IOException e){e.printStackTrace ();} {#0Tl
catch(Exception e){e.printStackTrace ();} t3K>\ :
2-PI JO
@_(nd57oSs
Utility.log(nFileLength); EI<"DB
{.cB>L
>*Sv0#
return nFileLength; )'w]YIv9
} Fr<Pe&dn
0:HC;J
<kROH0+
//保存下载信息（文件指针位置） D. 77WjwQ
private void write_nPos() F6~b#Jz&i
{ +$'e4EwqV
try{ 7Y4%R`9H
output = new DataOutputStream(new FileOutputStream(tmpFile)); p-a]"l+L
output.writeInt(nStartPos.length); ]}5`7
for(int i=0;i<nStartPos.length;i++) Q-:Ah:/
{ *P&OxVz
// output.writeLong(nPos); +V6j`
output.writeLong(fileSplitterFetch.nStartPos); rknzo]N,
output.writeLong(fileSplitterFetch.nEndPos); MG;4M>H
} IM$'J
output.close(); p$B)^S%0i
} 7jhl0
catch(IOException e){e.printStackTrace ();} T3 =)F%
catch(Exception e){e.printStackTrace ();} h)"'YzCt
} FyQOa)5
ZV0) ."^Z
#cR57=M}
//读取保存的下载信息（文件指针位置） pVdhj^n
private void read_nPos() kWI]fZ_n
{ Qh/lT$g
try{ )x y9X0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?exALv'B
int nCount = input.readInt(); cPx66Dh&
nStartPos = new long[nCount]; K,Lr+
nEndPos = new long[nCount]; oC5gME"2
for(int i=0;i<nStartPos.length;i++) >qr=l,Hi
{ F>p%2II/
nStartPos = input.readLong(); hU |LFjc
nEndPos = input.readLong(); }o~Tw?z-|
} )kFme=;
input.close(); ))c*_n
} :Xb*m85y
catch(IOException e){e.printStackTrace ();} :/ ~):tM
catch(Exception e){e.printStackTrace ();} g8C+1G8
} 9c#L{in
D-;J;m \
AviT+^7E
private void processErrorCode(int nErrorCode) u!sSgx=
{ ~Ay
System.err.println("Error Code : " + nErrorCode); S^*(ALFPj
} :h3#1fko
Fj'\v#h
E>o&GYc
//停止文件下载 #Lu4OSM+
public void siteStop() 8Ng))7g!
{ 1t!&xvhG
bStop = true; [RroHXdk+
for(int i=0;i<nStartPos.length;i++) h}Fu"zK
fileSplitterFetch.splitterStop(); Yk(NZ3O
wI|bBfd(
jJiCF,m
} g`y/_
} eW<!^Aer
//负责部分文件的抓取 E;ndw/GZjR
**FileSplitterFetch.java (\5<GCW-
*/ Lx|w~+k}
package NetFox; pmE1EDPag
Nj! R9N
ZYpD8u6U
import java.io.*; cj,&&3sbV
import java.net.*; &1\u#LU
oY| (M_;
XyN`BDFi
public class FileSplitterFetch extends Thread { yTMGISX5
?)i6:76(
gME:\ud$
String sURL; //File URL 9 ayH:;
long nStartPos; //File Snippet Start Position O% j,:t'"
long nEndPos; //File Snippet End Position So3,Z'z=
int nThreadID; //Thread's ID Cf8R2(-4
boolean bDownOver = false; //Downing is over lk5_s@V l
boolean bStop = false; //Stop identical $\=6."R5<
FileAccessI fileAccessI = null; //File Access interface w+:+r/!g
#)IdJ]
f?oI'5R41
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L>|A6S#y8/
{ fh/)di
this.sURL = sURL; 6PVlZ
this.nStartPos = nStart; 4jI*Y6Wkz
this.nEndPos = nEnd; ^;v.ytO*
nThreadID = id; *GY,h$Ul
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >-o?S O(M,
} _A# x&<c
;1Tpzm
5Lo==jHif
public void run() Y D1g]p
{ TU^tW
while(nStartPos < nEndPos && !bStop) hU=f?jo/
{ ]7Xs=>"Iw
EV;;N
Wl}G[>P
try{ `pn-fk
URL url = new URL(sURL); lSKv*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QQ2OZy>W
httpConnection.setRequestProperty("User-Agent","NetFox"); *>R/(Q
String sProperty = "bytes="+nStartPos+"-"; l-JKcsM
httpConnection.setRequestProperty("RANGE",sProperty); 'JXN*YO
Utility.log(sProperty); "@):*3 4
@5POgQ8
M\x7=*\
InputStream input = httpConnection.getInputStream(); `s]zk {x
//logResponseHead(httpConnection); G+%5V5GS
FZLzu
G/^5P5y%@
byte[] b = new byte[1024]; 'SXpb?CZ
int nRead; tF)k6*+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~=aI2(b
{ s;=J'x)~%
nStartPos += fileAccessI.write(b,0,nRead); G=0}IPfp
//if(nThreadID == 1) nY.Umj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YV>VA<c
} ce-m)o/
IT{.^rP
Z2Y583D
Utility.log("Thread " + nThreadID + " is over!"); wLg:YM"
bDownOver = true; V%Z[,C u+
//nPos = fileAccessI.write (b,0,nRead); 5#A1u Nb
} LP-KD
catch(Exception e){e.printStackTrace ();} (*@~HF,t=
} Yqj.z|}Nb
} \1c`)
[~&:`I1
_*-'yu8#
//打印回应的头信息 bU@>1>b6lE
public void logResponseHead(HttpURLConnection con) 1+y6W1m^R
{ &Cn9 k3E\R
for(int i=1;;i++) 4h0jX9
{ m0q`A5!)
String header=con.getHeaderFieldKey(i); =iQ`F$M
if(header!=null) 0DP%44Cv9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); azATKH+j
Utility.log(header+" : "+con.getHeaderField(header)); LKwUpu!
else &t@6qi`d
break; 8aIq#v
} jL[Is2<@
} ;Bc<u[G
9h{:!
"$wPq@
public void splitterStop() u{dN>}{
{ R,b O{2O
bStop = true; pOe`*2[
} Eo3Aak o
D-\'P31
"YJ;-$rb
} Hi 0df3t
3qwYicq,
@R Yb-d
/* q?'gwH37
**FileAccess.java kJ5?BdvM&
*//文件访问(定位，写) u\& [@v
package NetFox; SwmPP-n
import java.io.*; T"0)%k8lJ
oKqFZ,m[
8 H"f9S=K
public class FileAccessI implements Serializable{ !B38! L
P+cFp7nC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8=_| qy}l/
RandomAccessFile oSavedFile; mQ `r`DW
long nPos; frO/ nx|9
q.K$b
JnKbd~
public FileAccessI() throws IOException GeW$lA I
{ ^# g;"K0
this("",0); z4%F2Czai&
} W1,L>Az^Ts
|$-d,] V
-JW6@L@
public FileAccessI(String sName,long nPos) throws IOException .j$bCKXGx
{ 3'NL1du
oSavedFile = new RandomAccessFile(sName,"rw"); 9;WOqBD
this.nPos = nPos; Xcpm?aTo
oSavedFile.seek(nPos); 6}FDLBA
} x@RA1&c
CjukD%>sde
oL/^[TXjH
public synchronized int write(byte[] b,int nStart,int nLen) XjM)/-w
{ X;a{JjN
int n = -1; A2FU}Ym0=
try{ Kgio}y
oSavedFile.write(b,nStart,nLen); ;{C{V{
n = nLen; H_r'q9@<>
} ZN]c>w[ )I
catch(IOException e) >Ti2E+}[M
{ 0Y`tj
e.printStackTrace (); w*R-E4S?2
} Y8xnvK*
r{3`zqo
Xv(9 YhS
return n; X!+ a;wr
} ,$(v#Tz
v/6,eIz
CoN/L`.SN
} z7}zf@Y-qv
>Ezwl5b
Xr6 !b:UX
/* U[ungvU1U
**SiteInfoBean.java ?cxK~Y\
*/ }4ju2K
package NetFox; sWCm[HpG
JBJ7k19;
]O ` [v
public class SiteInfoBean { <UL|%9=~
9<r}s
p%y\`Nlgdx
private String sSiteURL; //Site's URL !>);}J!e]
private String sFilePath; //Saved File's Path 5K-)X9z?
private String sFileName; //Saved File's Name )CTM
private int nSplitter; //Count of Splited Downloading File e*Med)tc^$
1KR|i"
&>b1ES.>
public SiteInfoBean() ;l4\^E1
{//nSplitter的缺省值为5 9{#|sABGD
//default value of nSplitter is 5 'i-O
this("","","",5); n\p\*wb
} 491I
WQC6{^/4[1
-Dm.z16
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D;n%sRq(Z
{ ? UDvFQ&
sSiteURL= sURL; >RnMzH/9
sFilePath = sPath; F|K4zhK
sFileName = sName; A)\DPLAG
this.nSplitter = nSpiltter; 0qUap*fvC
1}M.}G2u/
meD (ja
} `v{X@x
i*/U.'#
E,:pIw
public String getSSiteURL() 9o'6es..@Z
{ F7l:*r,O
return sSiteURL; .*7UT~o=CS
} OIT;fKl9
wdV?&W+
ck+rOGv7{Z
public void setSSiteURL(String value) f)P/@rh
{ 6+z]MT
sSiteURL = value; i)3\jO0&GU
} ghj~r
\8aF(Y^H
nv{4 U}&P
public String getSFilePath() k|C8sSH
{ 5z>\'a1U
return sFilePath; R u-rp^a
} AAY UXY!
y]%,Y=%X
cN>i3}fq
public void setSFilePath(String value) =Q/>g6
{ I*2rS_i[T
sFilePath = value; #L$ I%L"
} ,e_#
[wG%@0\
ljON_*
public String getSFileName() hyoZh Y
{ `{_PSzM
return sFileName; Rw 8o]
} ZHasDZ8
a $%[!vF
uy:=V}p
public void setSFileName(String value) <J`xCm K
{ elB 8
sFileName = value; Zw{tuO7}K
} w5jZI|
mh]$g<*m
r/2:O92E
public int getNSplitter() `0D1Nh"%k
{ uJ\Nga<?
return nSplitter; `%p6i| _Q
} V~Lq,oth
sR.j~R
.&xNJdsY
public void setNSplitter(int nCount) 8m<<tv.
{ %MNV 5UA[w
nSplitter = nCount; b{Ss+F
} 2GzpWV(
} AMz=HN
R!G7;m'N1
Yk?q7xuT
/* G'f"w5%qZv
**Utility.java $SR]7GZ
*/ AgJ~6tK
package NetFox; %T\x~)
n<*]`do,w
8l0 (6x$
public class Utility { "M &4c:cz
o hlVc%a
I|z#Aoc
public Utility() 0 XzO`*
{ -~f.>@Wb
#+k[[; 0
yFsXI0I[p
} pnJT]?},
qTF>!o#\:
//线程睡眠 3PffQ,c[~
public static void sleep(int nSecond) Z+(V \
{ 5 ZPUY
try{ x~eEaD5m%J
Thread.sleep(nSecond); $uhDBmb
} zK?[dO
catch(Exception e) p04+"
{ "cM5=;
e.printStackTrace (); ^mQfXfuL
} y@_?3m7B=
} ~#\#!H7
F JhVbAMd
//日志 !*6z=:J
public static void log(String sMsg) q/79'>`|ai
{ 4&fnu/,Z
System.err.println(sMsg); =i?,y+<
} v19`7qgR(
2zu~#qU[)M
f34&:xz2U
public static void log(int sMsg) >~~\==".
{ G.TX1
System.err.println(sMsg); f4}6$>)
} K~T\q_ZPZ
} _xt(II
ku8c)
':4pH#E
/* ypo=y/!
**TestMethod.java U{(07GNm#
*/ aS G2K0
package NetFox; 7+4"+CA
8ZfIh
^MV%\0o
public class TestMethod { =]"|x7'!
ifZNl,
Ypj)6d
public TestMethod() bz]O(`
{ ///xx/weblogic60b2_win.exe oW6<7>1M7
try{ !H\GHA'DO]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .+h pxZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }* JMc+!9@
SiteFileFetch fileFetch = new SiteFileFetch(bean); a=VT|CX[
fileFetch.start(); x`i`]6q
} yVzg<%CR^
catch(Exception e){e.printStackTrace ();} :G/]rDtd
7g+]
#SNI dc>9\
} Fg_s'G,`
*PU,Rc()6
w[YbL2p
public static void main(String[] args) ygt)7f5
{ >]8.xkQq
new TestMethod(); UROi.976D
} q.{/{9
} /j@ `aG(a
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