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)); 3CzF@t;5
} 8`<e\g7-
for(int i=0;i<nEndPos.length-1;i++) >.M>,m\
{ X=+|(A,BdY
nEndPos = nStartPos[i+1]; w73?E#8
} nU4to
nEndPos[nEndPos.length-1] = nFileLength; IM% ,A5u
} 5U-SIG*
} 6r|=^3{
W#)X@TlE
8.,d`~
//启动子线程 P_4E<"eK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,,SV@y;
for(int i=0;i<nStartPos.length;i++) hK,a8%KnFA
{ 5cGQ`l
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6hMKAk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #f [}a
nStartPos,nEndPos,i); #c!rx%8I
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lqdapx"Z_
fileSplitterFetch.start(); }DQTy.d;P
} a^={X<K|/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fy]c=:EmD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UX+vU@Co[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T|8:_4/l
nEndPos = " + nFileLength); @@j:z;^|
// fileSplitterFetch[nPos.length-1].start(); "OwK-
]5K+W
[^Bjmw[7
//等待子线程结束 ?&'Kw>s@
//int count = 0; Q 0G5<:wc
//是否结束while循环 gu6%$z
boolean breakWhile = false; p}3` "L=
9: .m]QN
,z<1:st]<
while(!bStop) N]eBmv$|
{ 55'
write_nPos(); Y)@Y$_
Utility.sleep(500); EK= y!>
breakWhile = true; iciKjXJ:
NRny]!
xP_/5N=f
for(int i=0;i<nStartPos.length;i++) "u]&~$
{ GeDI\-
if(!fileSplitterFetch.bDownOver) ,]:Gn5~
{ ~`Rar2%B
breakWhile = false; ?JG^GD7D
break; k3H0$1
} DF_wMv:>^
} =&6sU{j*
if(breakWhile) .%y'q!?
break; ;>>n#8`
41R6V>e@9J
?"*JV1 9
//count++; HCsd$M;Hbv
//if(count>4) 5x%Blkx
// siteStop(); d#TA20`
} K-~gIlbQ`
JO*/UC>"
7nNNc[d*=
System.err.println("文件下载结束！"); CIz0Gjtx6m
} e pp04~
catch(Exception e){e.printStackTrace ();} 7*j!ZUzp
} F)KR8(
9Vqy<7i1
>s 6ye
//获得文件长度 ^D5Jqh)
public long getFileSize() V*ao@;sD
{ 76"4Q!
int nFileLength = -1; DI8<0.L
try{ `3i<jZMG
URL url = new URL(siteInfoBean.getSSiteURL()); PxgJ7d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a_+?#m
httpConnection.setRequestProperty("User-Agent","NetFox"); `vMhrn
y+T[="W
~uH_y-
int responseCode=httpConnection.getResponseCode(); 04jvrde8-O
if(responseCode>=400) Cdib{y<ji
{ L-}J=n\
processErrorCode(responseCode); (M"rpG>L
return -2; //-2 represent access is error ~5`oNa
} 5?F5xiW
^P^%Q)QXl
e*qGrg(E
String sHeader; E(j#R"
P woiX#vz
t))MZw&@
for(int i=1;;i++) ;:j1FOj
{ =qc+sMo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hrtz>qN
//Utility.log(in.readLine()); w8>h6x"
sHeader=httpConnection.getHeaderFieldKey(i); OtoM
if(sHeader!=null) aUzCKX%>C
{ bq9w@O
if(sHeader.equals("Content-Length")) u1L^INo/
{ }rI:pp^KS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "5Y6.$Cuf!
break; ?!&%-R6*
} Vn4wk>b}$2
} :u./"[G
else 7dcR@v`c
break; *s*Y uY%y
} \?>M?6D
} IC&P-X_aP
catch(IOException e){e.printStackTrace ();} 'Zp{
catch(Exception e){e.printStackTrace ();} i? ~-%
Nwz?*~1
/$CTz xd1
Utility.log(nFileLength); RzjUrt
l>}f{az-T
\$ipnQv
return nFileLength; t$z[ja=
} Nw'03Jzx_
O`c50yY
]vlBYAW'
//保存下载信息（文件指针位置） R`cP%7K
private void write_nPos() X0u,QSt'O
{ q50F!yHC-
try{ /3,Lp-kp
output = new DataOutputStream(new FileOutputStream(tmpFile)); >PSO]%mE
output.writeInt(nStartPos.length); q:/df]Ntt
for(int i=0;i<nStartPos.length;i++) 3y6\0|{1
{ 8rH6L:]S
// output.writeLong(nPos); X)[tb]U/Wx
output.writeLong(fileSplitterFetch.nStartPos); }a||@unr
output.writeLong(fileSplitterFetch.nEndPos); -p&u=
} d(o=)!p
output.close(); A}SGw.3
} PQkw)D<n]_
catch(IOException e){e.printStackTrace ();} ve ysW(z
catch(Exception e){e.printStackTrace ();} Zt!A!Afu
} Os@b8V 8,A
Ha`N
nf/?7~3?[
//读取保存的下载信息（文件指针位置） b/'c h
private void read_nPos() ZrTB%
{ X+aQ 7^"s
try{ = 'NV3by
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C~B ]@xxK)
int nCount = input.readInt(); ^;RK-)
nStartPos = new long[nCount]; [|OII!"
nEndPos = new long[nCount]; P[WkW#
for(int i=0;i<nStartPos.length;i++) Gv&G2^
{ +QU>D:l
nStartPos = input.readLong(); Sp80xV_B
nEndPos = input.readLong(); 3&+dyhL'w
} Z5>~l
input.close(); D#b*M)X"
} 8x U*j
catch(IOException e){e.printStackTrace ();} -!Myw&*\V
catch(Exception e){e.printStackTrace ();} A/>Q5)
} a)JXxst
=Z
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private void processErrorCode(int nErrorCode) YpDJ(61+
{ z6iKIw $
System.err.println("Error Code : " + nErrorCode); 25)9R^
} TC?B_;a
cjEqN8
$V(]z`b&
//停止文件下载 TU0-L35P1
public void siteStop() D=-}&w_T"
{ v.Ba
bStop = true; Q?k*3A
for(int i=0;i<nStartPos.length;i++) {R!yw`#^B
fileSplitterFetch.splitterStop(); ZwS:Te9-
ma~#E$i&
\b"rf697,
} 'RMUjJ-!
} b&U1^{(
//负责部分文件的抓取 '`P%;/z
**FileSplitterFetch.java Y[6T7eZ0g
*/ J,yKO(}<C
package NetFox; (`.OS)&
('5?-
bQt:=>
import java.io.*; R+M=)Z
import java.net.*; g#J aw|N
35& ^spb
h=7q;-@7
public class FileSplitterFetch extends Thread { b_31\
vFVUdxPOw
zFq%[X
String sURL; //File URL !4vb{AH
long nStartPos; //File Snippet Start Position VGV-t
long nEndPos; //File Snippet End Position N'v3 |g
int nThreadID; //Thread's ID UphTMyn3
boolean bDownOver = false; //Downing is over y|5s
boolean bStop = false; //Stop identical r)iEtT!p*
FileAccessI fileAccessI = null; //File Access interface ~T1W-ig4[*
+.V+@!
-F~DOG%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d.wGO]"
{ Tc6cBe,
this.sURL = sURL; @V%\Gspv
this.nStartPos = nStart; V)^Xz8H_
this.nEndPos = nEnd; :\OSHs<M
nThreadID = id; q-JTGCFl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #d-({blo<
} 1>J.kQR^
H#TkIFo]
+` Md5.w
public void run() ?F"o+]i+^
{ :,l7e
while(nStartPos < nEndPos && !bStop) a: "1LnvR
{ SyvoN,;Q
iHD!v7d7
2LwJ%!
try{ "I.6/9
URL url = new URL(sURL); h6h6B.\Ld
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cE]z Tu?!
httpConnection.setRequestProperty("User-Agent","NetFox"); =}`d
String sProperty = "bytes="+nStartPos+"-"; D\Ak-$kJ^
httpConnection.setRequestProperty("RANGE",sProperty); GcVQz[E
Utility.log(sProperty); ]8p{A#1
<Ua~+U(FR0
w]wZJ/U`
InputStream input = httpConnection.getInputStream(); | &X<-
//logResponseHead(httpConnection); 3Vk8'
_?c.m*)A
axC|,8~tq
byte[] b = new byte[1024]; Z=JKBoAY
int nRead; 1sqE/-v1_^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5)#j}`6
{ yfG;OnkZ
nStartPos += fileAccessI.write(b,0,nRead); 46:<[0Psl/
//if(nThreadID == 1) o:d7IL
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a"vzC$Hxd
} Lw>B:3e
[6!k:-t+
$Rm~ VwY#
Utility.log("Thread " + nThreadID + " is over!"); Fw<"]*iu
bDownOver = true; @Q74
//nPos = fileAccessI.write (b,0,nRead); *S;}&VAZ
} 7V"?o
catch(Exception e){e.printStackTrace ();} b"I#\;Ym
} 2 2v"?*
} cgb>Naa<
h.\I tK{)
Tv``\<
//打印回应的头信息 l9.`2d]o
public void logResponseHead(HttpURLConnection con) *qpu!z2m||
{ u[GZ~L
for(int i=1;;i++) WcN4ff-
{ :aNjh
String header=con.getHeaderFieldKey(i); -"[4E0g0
if(header!=null) (p{X.X+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )d3 09O
Utility.log(header+" : "+con.getHeaderField(header)); ,?GwA@~$k:
else j 3<Ci {3
break; ]es|%j 2
} dSGdK $XA
} ]\39#
#/G!nN #
~fXNj-'RW
public void splitterStop() vpu#!(N
{ Ik:G5m<ta
bStop = true; aq?bI:>8
} u+)!C*ho
?@"@9na
=Vg~ VD
} yq~
?{J1&;j*
L=<xTbY
/* Thggas,
**FileAccess.java 7U [C=NL
*//文件访问(定位，写) JU8}TX
package NetFox; Za@\=}Tt
import java.io.*; f.g!~wGD
Pp?P9s{
g#I`P&
public class FileAccessI implements Serializable{ ioi/`iQR
wkt4vE87
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qCI&H7u@
RandomAccessFile oSavedFile; x^y$pr
long nPos; khX/xL
uz3cho'
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public FileAccessI() throws IOException +R~]5Rxd
{ }u^bTR?3
this("",0); #]Vw$X_S
} ( fFrX_K]
IjhRSrCv
uI,*&bP
public FileAccessI(String sName,long nPos) throws IOException ZcA"HD%
{ :V9Q<B^
oSavedFile = new RandomAccessFile(sName,"rw"); amsl>wc!
this.nPos = nPos; S]H[&o1o
oSavedFile.seek(nPos); 48p3m)5
} KDN#CU
L4iWR/&
whI4@#
public synchronized int write(byte[] b,int nStart,int nLen) R&uPoY,f
{ I(6%'s2
int n = -1; cC8$oCR?
try{ ihkZs3}
oSavedFile.write(b,nStart,nLen); Gb^63.}
n = nLen; i3 js'?7E
} h),;j`PrC
catch(IOException e) IsE&k2 SD
{ {tVA(&\<
e.printStackTrace (); jnV#Q ;
} Gr({30"8
q~qz^E\T
sD3Ts;k
return n; }%KQrlbHJl
} "|6(.S+o
S%RxYJ(
b8a(.}8*
} 6Emn@Mn=
S(=@2A+;
c:${qY:!
/* rT="ciQ
**SiteInfoBean.java ,IiKe_B
*/ B~o3Z
package NetFox; -IIrrY O
Qz`evvH
q`AsnAzo&
public class SiteInfoBean { -t_&H\_T
yc0 1\o
d^'_H>x
private String sSiteURL; //Site's URL ygTfQtN
private String sFilePath; //Saved File's Path Z@q1&}D!
private String sFileName; //Saved File's Name )+FnwW
private int nSplitter; //Count of Splited Downloading File <_/etw86Z
/:!sn-(
5+GTK)D
public SiteInfoBean() @!$xSH
{//nSplitter的缺省值为5 ,$]m1|t@z
//default value of nSplitter is 5 +^:uPW^U
this("","","",5); ufR|V-BWx
} IlEU6Rs
[<+T@"y
YWPkVvI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KMT$/I{p,
{ uJ"#j X
sSiteURL= sURL; UHJro9
sFilePath = sPath; ZV Ko$q:F
sFileName = sName; ycN!N
this.nSplitter = nSpiltter; PR;Bxy
''2:ZXX
1sUgjyGQ
} zRh)q,Dt
$zz4A~
`DSDuJw%
public String getSSiteURL() .==c~>N
{ QP%AJ[3ea%
return sSiteURL; .9DhD=8aIO
} ,-])[u
OfLj 4H6Q
u}'m7|)8
public void setSSiteURL(String value) d3oRan}z
{ )m-(-I
sSiteURL = value; Z){fie4WM
} 9'X"a
g9GPyU
=j_4!^
public String getSFilePath() !rx5i
{ nJH'^rO!C
return sFilePath; ;&b=>kPlZ
} 6/a%%1c1
KYhL}C+
o &b\bK%E
public void setSFilePath(String value) '<"%>-^Gn
{ i[/1AI
sFilePath = value; |}l/6WHB
} SOD3MsAK
1\TkI=N3
B \V;{:
public String getSFileName() c3fd6Je5
{ x}C$/7^
return sFileName; {s@&3i?ZiC
} LWo)x
JpQV7}$
lfoPFJ Z
public void setSFileName(String value) 8yr-X!eF
{ PtjAu
sFileName = value; @ /e{-Q
} 7vqE@;:dt
yrzyus
Dmtsu2o
public int getNSplitter() %)}_OXWf:
{ ZA4sEVHW
return nSplitter; ^]LWcJ?"^!
} S{cK~sZj
'pAq;2AA
Ud-c+, xX
public void setNSplitter(int nCount) B)DtJf
{ wh]v{Fi'
nSplitter = nCount; <.|]%7
} voN,u>U
} NS4W!o;"
T.!.3B$@]
:2L-Nf
/* 7r3EMX\#Qm
**Utility.java P\X$fD
*/ %F*h}i
package NetFox; >+BLD
Kn+B):OY+
Xp^71A?>
public class Utility { btf]~YN
bmC{d
l%cE o`U
public Utility() yV@~B;eW0
{ xqVIw!J?/}
U,9=&"e b
Jpe\
} Nrp1`qY
P= 26! b
//线程睡眠 v~O2y>8Z
public static void sleep(int nSecond) oFJx8XU
{ %tz foiJ%P
try{ orF8%
Thread.sleep(nSecond); kEdAt5/U{
} 62OZj%CXN
catch(Exception e) &ZPyZj
{ |A u+^#:;
e.printStackTrace (); j|WN!!7
} 'k$j^|r>
} -[lOf
DTV"~>@
//日志 $Jy1=/W&
public static void log(String sMsg) E7Pz~6
{ ]\%u9,b%!
System.err.println(sMsg); BG20R=p
} JLxAk14lc
gM#]o QOGE
wtro'r3
public static void log(int sMsg) 4q^'MZm1
{ DmpD`^?-L
System.err.println(sMsg); yFqB2(Dv
} GA)t!Xg^
} , rc %#eF
"M:0lUy
jTz~ V&^
/* %wux#"8
**TestMethod.java &p^8zEs
*/ 20RISj
package NetFox; RC]-9gd3Q
Hn,;G`{
^&8xfI6?
public class TestMethod { w`K=J!5y2g
[Gb8o'
[,ns/*f3R
public TestMethod() w>gB&59r
{ ///xx/weblogic60b2_win.exe ~@Eu4ip)F
try{ Hk|wO:7Be
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g~$cnU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |`6*~ciUV
SiteFileFetch fileFetch = new SiteFileFetch(bean); H(j983
fileFetch.start(); b\Gw|?Rv
} DlbNW& V
catch(Exception e){e.printStackTrace ();} w57D qG>
L(qQ,1VY
r5aOQ
} *U^7MU0
Wi{ jC?2Q
EJ`"npU
public static void main(String[] args) n[`FoY
{ /q>1X!Z
new TestMethod(); UgZuEfEGve
} N(^ q%eHp
} ).1F0T
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