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)); Fu[<zA^
} y4j\y ? T8
for(int i=0;i<nEndPos.length-1;i++) H_d^Xk QZ
{ VhLS*YiSY
nEndPos = nStartPos[i+1]; >h{)7Hv
} b;IzK'
nEndPos[nEndPos.length-1] = nFileLength; J)._&O$
} 0Q!/A5z
} !YENJJ
cN%@ nW0i
1}ws@hU
//启动子线程 -xL^UcG0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >Q[3t79^
for(int i=0;i<nStartPos.length;i++) ^:Fj+d
{ ,j e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f:KZP;/[c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \t?rHB3"
nStartPos,nEndPos,i); QyD(@MFxb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *1g3,NMA
fileSplitterFetch.start(); k]9+/$
} tx,q=.(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @!p0<&R@x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W}'l8z]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Mew,g:m:
nEndPos = " + nFileLength); %Z+FX,AK
// fileSplitterFetch[nPos.length-1].start(); H_FT%`iM
;C,t`(
JiFB<Q\
//等待子线程结束 &.[I}KH|B
//int count = 0; 4n6t(/]b<
//是否结束while循环 ,C0D|q4/!.
boolean breakWhile = false; 7[ZoUWx
vE&K!k`
9NeHN@D)
while(!bStop) Y@ X>ejk"
{ bkFO4OZd
write_nPos(); N^f_hL|:9
Utility.sleep(500); .,<w_=
breakWhile = true; q0L\{
]]XXcQ,A
W:JR\KKU
for(int i=0;i<nStartPos.length;i++) o'K= X E
{ N^4CA@'{
if(!fileSplitterFetch.bDownOver) xiOAj"}~
{ sQBKzvFO3
breakWhile = false; Q PrP3DK
break; &X#6jTh+
} r7-H`%.
} }h1y^fuGi
if(breakWhile) -8:/My
break; C2H2*"
W#kd[Wi
<RuLIu
//count++; {'sp8:$a
//if(count>4) %\T#Ik~3
// siteStop(); 5O[\gd-
} #@L5yy2
\1<8'at
~(\.j=x
System.err.println("文件下载结束！"); ;e6L@)dp9
} >!bw8lVV
catch(Exception e){e.printStackTrace ();} 3v~[kVhoG
} 7ygz52
^~^=$fz
sGG q~7
//获得文件长度 Cs2kbG_
public long getFileSize() KzQuLD(e
{ @]etW>F_
int nFileLength = -1; ^ddC a
try{ eh}|Wd7J
URL url = new URL(siteInfoBean.getSSiteURL()); X3'd~!a)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j937tn!Q
httpConnection.setRequestProperty("User-Agent","NetFox"); .f&Z+MQ
Hi nJ}MF
VUC_|=?dL
int responseCode=httpConnection.getResponseCode(); y+h/jEbM</
if(responseCode>=400) Yf_/c*t\5
{ m-]F]c=)w<
processErrorCode(responseCode); Cd|rDa
return -2; //-2 represent access is error >4bWXb'S}C
} o:`^1
`=%G&_3_<
8ib e#jlg
String sHeader; SB,#y>Zv?
f`YHZ O
49= K]X
for(int i=1;;i++) kn+@)3W:*
{ +2>, -V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .EZ8yJj1Q
//Utility.log(in.readLine()); .>1vN+
sHeader=httpConnection.getHeaderFieldKey(i); ?(M$r\\
if(sHeader!=null) E:Ul_m8
{ V/tl-;W
if(sHeader.equals("Content-Length")) mc4|@p*
{ 39A|6>-?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); is=x6G*r
break; 5Gm8U"UR
} NIHcX6Nw
} ZEs^b
else m -0}Pe9L
break; :-$TD('F
} a:KL{e[
} x>+sqFd\
catch(IOException e){e.printStackTrace ();} 2M)E1q|a
catch(Exception e){e.printStackTrace ();} f9t+x+ Z
ZB]234`0
LI>Bl
Utility.log(nFileLength); <?%49
r,q.RWuII
Y$_^f*sFn
return nFileLength; vAjog])9s
} h+w1 D}*
mR~S$6cc
yji>vJHu
//保存下载信息（文件指针位置） =3PZGdWD
private void write_nPos() lo-VfKvy
{ }(oWXwFb&W
try{ xeKm} MN]S
output = new DataOutputStream(new FileOutputStream(tmpFile)); \H 5t-w=
output.writeInt(nStartPos.length); 8%p+:6kP5
for(int i=0;i<nStartPos.length;i++) pZ]&M@Ijp
{ <) -]'@*c
// output.writeLong(nPos); 5=V29
output.writeLong(fileSplitterFetch.nStartPos); t ?05
output.writeLong(fileSplitterFetch.nEndPos); 5"bg8hL
} [AYJ(H/
output.close(); zb s7G
} VVfTFi<
catch(IOException e){e.printStackTrace ();} O^8=Xj#}
catch(Exception e){e.printStackTrace ();} (yoF
} ZCA= n
V P(JV
7Kpv fyL{
//读取保存的下载信息（文件指针位置） G?!8T91;
private void read_nPos() *+(eH#_2/
{ .g94|P
try{ nI] zRduC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); js!C`]1
int nCount = input.readInt(); *VUJ);7k
nStartPos = new long[nCount]; HY;kV6g{P
nEndPos = new long[nCount]; /J9Or{#r
for(int i=0;i<nStartPos.length;i++) 0IZF%`
{ X{:3UTBR
nStartPos = input.readLong(); ,;Uf>8~
nEndPos = input.readLong(); rr>6;
} K5z<n0X ~
input.close(); OTNI@jQ)
} _Ud!tK*H
catch(IOException e){e.printStackTrace ();} +pQ3bX
catch(Exception e){e.printStackTrace ();} u95D0S
} qpzyl~g:C
M!X^2
|io)?`pj
private void processErrorCode(int nErrorCode) -Rx;"J.H
{ PEaZ3{-
System.err.println("Error Code : " + nErrorCode); :ciD!Ly
} 7Hj7b:3K&!
bDD29
mQ9shdvt-
//停止文件下载 'T7Y5X80$j
public void siteStop() <9c{Kt.5(
{ wk'&n^_br
bStop = true; >CwI(vXn
for(int i=0;i<nStartPos.length;i++) Eo6qC?5<
fileSplitterFetch.splitterStop(); $LcMG,8%_
}}bMq.Q'
=J]M#6N0
} 9W-1P}e,
} i 1Kq(7
//负责部分文件的抓取 \GKR(~f
**FileSplitterFetch.java h8-uI.RZ
*/ }a#=c*+_
package NetFox; (Ffa{Tt!
wc\`2(
mHa~c(x
import java.io.*; sHPj_d#
import java.net.*; "<f?.l\+
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public class FileSplitterFetch extends Thread { [)il_3t
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String sURL; //File URL 0uIBaW3s
long nStartPos; //File Snippet Start Position M#Q"h5l
long nEndPos; //File Snippet End Position wWSE[S$V
int nThreadID; //Thread's ID K3h"oVn
boolean bDownOver = false; //Downing is over y\[q2M<
boolean bStop = false; //Stop identical ?b93! Q1
FileAccessI fileAccessI = null; //File Access interface O}j@+p%M
87m`K Str7
f1?%p)C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wA6E7vi'
{ -B(p8YH
this.sURL = sURL; [k&7h,
this.nStartPos = nStart; w,_LC)9
this.nEndPos = nEnd; I3}]MAE
nThreadID = id; B\qy:nr j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =kCiJ8q|
} }^P"R[+4u
2|U6dLZ!
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public void run() yU"#2 *C
{ j8]M}Q$
while(nStartPos < nEndPos && !bStop) P>$+XrTE
{ ;jO+<~YP!
|;^$IZSsz
"KSdC8MS
try{ U??OiKVZ+
URL url = new URL(sURL); }SyK)W5Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); THB[(3q
httpConnection.setRequestProperty("User-Agent","NetFox"); zU!d(ge.E
String sProperty = "bytes="+nStartPos+"-"; q8,,[R_
httpConnection.setRequestProperty("RANGE",sProperty); k~F,n
Utility.log(sProperty); *I}_g4
hS>=pO+y
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InputStream input = httpConnection.getInputStream(); wDW/?lT&
//logResponseHead(httpConnection); <q Q@OUI
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de[NIDA;`
byte[] b = new byte[1024]; `LKf$cx(A
int nRead; ;%cW[*Dw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *P&lAyt6
{ g>`D!n::n
nStartPos += fileAccessI.write(b,0,nRead); B__e*d:)!m
//if(nThreadID == 1) GiXs`Yt|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5@ Hg 4.
} Ekh)l0 l
G({VK
/gex0w
Utility.log("Thread " + nThreadID + " is over!"); JSaF7(a =
bDownOver = true; tV4wkS=R|
//nPos = fileAccessI.write (b,0,nRead); =h+-1zp{M^
} cIK4sOTJ&
catch(Exception e){e.printStackTrace ();} _1WA:7$C
} %b~ND?nn-
} /zr)9LQY0
$vn)(zn+
Bgp%hK
//打印回应的头信息 fZ^ad1o
public void logResponseHead(HttpURLConnection con) ~y whl'"k
{ ] ;HCt=I~
for(int i=1;;i++) ^t$uDQ[hA
{ ;Cjj_9e,:
String header=con.getHeaderFieldKey(i); dxH.
if(header!=null) y(E<MRd8V
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z|)1ftcC
Utility.log(header+" : "+con.getHeaderField(header)); {~G~=sC$
else 8Z)wot
break; ?crK613 t
} l-x-
} |CQ0{1R1
]86*k%A
9E4^hkD&
public void splitterStop() +At0V(
{ '+'h^
bStop = true; ULs'oT)K;
} 2OqEyXh
|$+/IxDP
@=Dc(5`[
} `DM)tm3&m
Y##lFEt
h`(VMf'#
/* s0Z)BR #
**FileAccess.java }r;=<mc,O
*//文件访问(定位，写) YN7`18u
package NetFox; g`tV^b")
import java.io.*; "D KrQ,L
Md8<IFi9]Q
Y]5MM:mI
public class FileAccessI implements Serializable{ `)MKCw$e
q!~DCv df
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [$:L|V!{
RandomAccessFile oSavedFile; 8U7dd[
long nPos; Lr=^0
,}9 tJY@E
h-SKw=n
public FileAccessI() throws IOException 6Tc!=lk
{ E}<i?;
this("",0); ~&+a.@T
} eZ0-O /_i
>p" U|
oq|`;k
public FileAccessI(String sName,long nPos) throws IOException _A0X[}^K
{ nE2?3S>
oSavedFile = new RandomAccessFile(sName,"rw"); BN&}g}N
this.nPos = nPos; c6y>]8_
oSavedFile.seek(nPos); "=JE12=u
} /FC(d5I
8HHR
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public synchronized int write(byte[] b,int nStart,int nLen) ={;+0Wjb8
{ m}S}fH(
int n = -1; W5~!)Ec
try{ :_=YH+bZ
oSavedFile.write(b,nStart,nLen); 6s ~!B{Q
n = nLen; WT3g31
} :VLYF$|
catch(IOException e) Q/*|ADoq
{ 1+Ik\
e.printStackTrace (); VUz+_)
} FN (O
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wbh=v;
return n; GaL UZviJ_
} 9\=SG"e(
cqW(9A|8
ZPz=\^
} NzeiGj
[;ZC_fD
vF>]9sMv
/* (A=Z,ed
**SiteInfoBean.java $H]NC-\+>
*/ n.R"n9v`
package NetFox; cRNVqMpg
GdrVH,j
S2W@;XvV
public class SiteInfoBean { ^\Q%VTM
r6:e 423
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private String sSiteURL; //Site's URL {Ve`VV5E
private String sFilePath; //Saved File's Path _={mKKoHs
private String sFileName; //Saved File's Name '* /$66|
private int nSplitter; //Count of Splited Downloading File y7GgTC/H
B?y[ %i
?8U]UM6Tu4
public SiteInfoBean() OjqT5<U
{//nSplitter的缺省值为5 EQ|Wke
//default value of nSplitter is 5 m&be55M;
this("","","",5); 3"k n5)x
} 3SPXJa\i
6K=}n] n
D]|{xKC}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kc}|L9
{ AR&l9R[{N
sSiteURL= sURL; >B*zzj
sFilePath = sPath; ~,xso0
sFileName = sName; @U1t~f^
this.nSplitter = nSpiltter; P97i<pB Y_
gkKNOus
BW`;QF<
} v$5D&Tv
{ 9\/aXPS
2t45/:,
public String getSSiteURL() ^uVPN1}b^@
{ b.kV>K"X3
return sSiteURL; P_75-0G
} 036QV M$
bqx2lQf,_
HEhBOER?
public void setSSiteURL(String value) )p:+!sX(
{ &n0Ag]$P
sSiteURL = value; I9`ZK2S
} \g)?7>M|
:m/qR74+"
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public String getSFilePath() ,Z! I^
{ C',uY7}<
return sFilePath; pr,1pqiAf
} AI9922}*
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\$F#bIjC
public void setSFilePath(String value) z3>4 xn{
{ ap"pQ[t;
sFilePath = value; EVA&By6_k
} u),.q7(m
5l%g3F
bUSa#pNO>
public String getSFileName() W{j(=<|<
{ N%e^2O)
return sFileName; ]&P 4QT)f
} *Ue#Sade
2:e7'}\D.
b' ~WS4xlD
public void setSFileName(String value) .0;\cv4}
{ :QXKG8^
sFileName = value; 7+hc?H[&'
} ua_,c\iL
W%o! m,zFM
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public int getNSplitter() *Gj`1#Z$
{ Ag8lI+ h
return nSplitter; 1Y~'U =9
} 4-$kcwA
6Lg#co}9
3 +`,'Q9
public void setNSplitter(int nCount) fRkx ^u P
{ 6k<3,`VV|
nSplitter = nCount; x;LO{S4Z
} b5f+q:?{
} Wc;N;K52
roe_H>
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/* B[+b%a3
**Utility.java c+8 Y|GB
*/ _x,(576~
package NetFox; /ZH*t\
NJOV!\k
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public class Utility { CoWT
&SPr#OkW
ilZ5a&X;
public Utility() T eu.i
{ iQLP~Z>,T
X\*H7;k,
"1%k"+&
} Kq+vAp).
lE8_Q*ev
//线程睡眠 Vf=,@7
public static void sleep(int nSecond) Rd5pLrr[0)
{ |W&K@g$
try{ g9d/nRX&
Thread.sleep(nSecond); q~*|Wd'&
} o? K>ji!
catch(Exception e) ]"j%:fr
{ */$]kE
e.printStackTrace (); (Fq]y5
} oU*e=uehj
} Y ._Om}H
-B-HZ_
//日志 .f!:@fX>=
public static void log(String sMsg) G%h+KTw
{ 7;?7q
System.err.println(sMsg); f3:dn7
} RK)ikLgp
|I|,6*)xg
%+UTs'I
public static void log(int sMsg) ft iAty0n
{ ]I;owk,
System.err.println(sMsg); o_[I#PT
} yBv4 xKMH
} NL!xkcXO
.v9i|E=<~
BrZ17
/* Q^?$2ck=
**TestMethod.java {?X +Yw
*/ ;CV'
package NetFox; Z 8GIZ
g|4>S<uC
^?0?*
public class TestMethod { %(s2{$3
ma"M?aM
A v;NQt8ut
public TestMethod() dKw[#(m5v
{ ///xx/weblogic60b2_win.exe %uo#<Ny/ I
try{ c^5fhmlt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); th0>u.hJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >km$zfM2-
SiteFileFetch fileFetch = new SiteFileFetch(bean); pNu?DF{ 3
fileFetch.start(); ,I,Zl.5
} [g+WL\1
catch(Exception e){e.printStackTrace ();} =OKUSHu@V
L%pAEoSG
(+u&b< <6N
} U-{3HHA
+]hc!s8
jDj=a->e^
public static void main(String[] args) >:J1Gc
{ EFu>
new TestMethod(); 4r7aZDVA\
} OXX D}-t
} =2}bQW
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