http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); 0\_R|i_`>
} ~qLhZR\g^
for(int i=0;i<nEndPos.length-1;i++) *Y^Y
{ *\~kjZ 3
nEndPos = nStartPos[i+1]; 66"ZH,335
} 9%)& }KK|
nEndPos[nEndPos.length-1] = nFileLength; @=<TA0;LL
} 6q xUT
} z5o9\.y({
C(%5,|6
M;RnH##W
//启动子线程 On96N|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BorfEv} SN
for(int i=0;i<nStartPos.length;i++) EH!EyNNb
{ 2h? r![
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n'ca*E(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $O]E$S${
nStartPos,nEndPos,i); z_,]fd=o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dXK~ Z:
fileSplitterFetch.start(); IDk:jO
} o}^vREO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yV]-Oa$*s0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %ucmJ-<y#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", * SON>BSF
nEndPos = " + nFileLength); tL4]6u
// fileSplitterFetch[nPos.length-1].start(); /jL{JF>I
[q+39
pvwnza1
//等待子线程结束 y88}f&z#5
//int count = 0; "y ,(9_#
//是否结束while循环 7Hkf7\JY
boolean breakWhile = false; Xi`U`7?D(=
[@FeRIu8
^CZ|ci6bX
while(!bStop) #y9K-}u
{ ^[\53\R~
write_nPos(); Ew,wNR`
Utility.sleep(500); [,A'
breakWhile = true; m"m;(T{ v
h}:5hi Jw
{R8P $
for(int i=0;i<nStartPos.length;i++) jeuNTDjeL
{ .STf
if(!fileSplitterFetch.bDownOver) NwuBe:"@
{ xg5@;p
breakWhile = false; au}0PnA;
break; u$/2XO
} ib=^tK
} fF]&{b~wk
if(breakWhile) Gt%?[
break; vFvu8*0
C%7)sLWjJS
X1z0'gvh
//count++; ]}Hv,a
//if(count>4) ^d$e^cU
// siteStop(); U &k3
} Pc ?G^ Xol
F1[[fH
3\l9Sf=M|
System.err.println("文件下载结束！"); ]~ 8N
} <.B> LU
catch(Exception e){e.printStackTrace ();} mt]YY<l
} wU3ica&[
5OqsnL_V
tZBE& :l
//获得文件长度 UHl/AM>!
public long getFileSize() t:@A)ip
{ >33b@)
int nFileLength = -1; <^c0bY1
try{ nk,Mo5iqV
URL url = new URL(siteInfoBean.getSSiteURL()); T`<k4ur
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `e;Sjf<
httpConnection.setRequestProperty("User-Agent","NetFox"); ZTz(NS EK
x3F L/^S
#K*q(ei,7h
int responseCode=httpConnection.getResponseCode(); QS?9&+JM|
if(responseCode>=400) mb6?$1j
{ [goPmVe+
processErrorCode(responseCode); #"YWz)8
return -2; //-2 represent access is error -ddatc|
} x=|@AFI
{j4:.fD
w)SxwlW}
String sHeader; _Wsk3AP
tJfN6
bD[W~ku
for(int i=1;;i++) \bmboNe
{ O.f3 (e!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X?xm1|\
//Utility.log(in.readLine()); c@{^3V##T
sHeader=httpConnection.getHeaderFieldKey(i); Vk=<,<BB
if(sHeader!=null) f5XcBW9E
{ 0~5}F^8[L
if(sHeader.equals("Content-Length")) uXa}<=O
{ R,Uy3N
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); @!HMd{r
break; w|*G`~l09
} T<,tC"
} z9c=e46O
else \Le#+P
break; zq>"a&Y,
} (MU7
} F?Nk:# V
catch(IOException e){e.printStackTrace ();} =umS^fJ5`
catch(Exception e){e.printStackTrace ();} 2*E<G|-F
Z+Zh;Ms
%cjav
Utility.log(nFileLength); l_IX+4(@b|
D\~$6#B>>
o6%f%:&
return nFileLength; MNE)<vw>
} jl29~^@}1i
D)$k{v#~
wpMQ 7:j
//保存下载信息（文件指针位置） SvrV5X
private void write_nPos() KAEpFobYo
{ U.jMK{
try{ I4ct``Di
output = new DataOutputStream(new FileOutputStream(tmpFile)); :dc J6
output.writeInt(nStartPos.length); u3!!_~6,z
for(int i=0;i<nStartPos.length;i++) G?(:Z=
{ y`Y}P1y*
// output.writeLong(nPos); 01w/,r
output.writeLong(fileSplitterFetch.nStartPos); $l"(tB7d
output.writeLong(fileSplitterFetch.nEndPos); 0tyU%z{RV
} E&v-(0
output.close(); 82l";;n4p
} gvt4'kp
catch(IOException e){e.printStackTrace ();} 0kEq|k9
catch(Exception e){e.printStackTrace ();} skArocs
} RtEkd_2
l'R`XGT
88U
//读取保存的下载信息（文件指针位置） (jMp`4P
private void read_nPos() }Ec"&
{ lK@r?w|<M
try{ '*.};t~;"d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); : P2;9+v
int nCount = input.readInt(); ~qxc!k!w4
nStartPos = new long[nCount]; 2M`Ni&v
nEndPos = new long[nCount]; ^ZBkt7
for(int i=0;i<nStartPos.length;i++) m>:ig\
{ nJw1Sl5
nStartPos = input.readLong(); l,8|E
nEndPos = input.readLong(); #r}c<?>Vw
} (P_+m#
input.close(); AIo;\35
} |%9~W^b
catch(IOException e){e.printStackTrace ();} [a6lE"yr
catch(Exception e){e.printStackTrace ();} 3F3?be
} B-zt(HG
L1+cv;t
pgi7 JQ
private void processErrorCode(int nErrorCode) pYQs|5d
{ sIM`Q%
System.err.println("Error Code : " + nErrorCode); XRin~wz|S
} b6VAyTa
SS-
}DwXs`M7
//停止文件下载 Q5ao2-\
public void siteStop() 4 .qjTR
{ VW/1[?HG5
bStop = true; h@8
for(int i=0;i<nStartPos.length;i++) W`kgYGnFG
fileSplitterFetch.splitterStop(); .!! yj,bQz
v]sGdZ(6-
3M`J.>
} ea/6$f9^
} N~YeAe~+
//负责部分文件的抓取 **[p{R]8o
**FileSplitterFetch.java b*7i&q'H
*/ =="SW"vNi
package NetFox; uEY5&wX`
,;}RIcvQV
"b;?2_w:E
import java.io.*; =cY]cPO
import java.net.*; n9ih^H
?,[w6O*
ujBADDwOg)
public class FileSplitterFetch extends Thread { lnUy?0(
=n&83MYX
Pd?YS!+S
String sURL; //File URL }qg&2M%\
long nStartPos; //File Snippet Start Position oKiu6=
long nEndPos; //File Snippet End Position &aU+6'+QXB
int nThreadID; //Thread's ID 8iB}a\]B
boolean bDownOver = false; //Downing is over c=CXj3
boolean bStop = false; //Stop identical OYkd?LN
FileAccessI fileAccessI = null; //File Access interface !LA#c'
IuL]V TY
u^$ CR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %8/$CR
{ x(Z@R\C-a
this.sURL = sURL; =>U~ligu
this.nStartPos = nStart; 7;V5hul
this.nEndPos = nEnd; "`wq:$R
nThreadID = id; 2J5dZYW
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8h=XQf6k0
} c@P,
dEnhNPeRl
*BV .zbGm
public void run() #;)7~69
{ S3r\)5%;
while(nStartPos < nEndPos && !bStop) s Y,3
{ el<nY"c
rkrt.B
*9PQJeyR
try{ g$qh(Z_s
URL url = new URL(sURL); nK[$ID
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -=Hr|AhE
httpConnection.setRequestProperty("User-Agent","NetFox"); +( d2hSIF
String sProperty = "bytes="+nStartPos+"-"; Phczf
httpConnection.setRequestProperty("RANGE",sProperty); f.{0P-Np
Utility.log(sProperty); ( KrIMZ
~kga+H
= zSrre
InputStream input = httpConnection.getInputStream(); Ra5cfkH;
//logResponseHead(httpConnection); WF]:?WE%
\`^jl
g|oPRC$I'
byte[] b = new byte[1024]; C%&7,F7
int nRead; :>5]A6Wi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~tWBCq 6
{ aNz%vbh\
nStartPos += fileAccessI.write(b,0,nRead); /:DxB00
//if(nThreadID == 1) b< rM3P;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Lv"83$^S9
} W~qo `r
uE2Yn`Ha
ME(!xI//JZ
Utility.log("Thread " + nThreadID + " is over!"); fHiCuF
bDownOver = true; mTt 9 o9E
//nPos = fileAccessI.write (b,0,nRead); T &1sfS,
} E_z@\z MB
catch(Exception e){e.printStackTrace ();} =[$*PTe
} JmK+#o
} a;(:iMCi
>3JOQ;:d8
DI\^+P
//打印回应的头信息 9f "*Oj
public void logResponseHead(HttpURLConnection con) CfAqMH*ip
{ 0t~--/lA
for(int i=1;;i++) x8H)m+AW
{ Hi9]M3Ub
String header=con.getHeaderFieldKey(i); ;J:YNup
if(header!=null) p81~Lk*Hz@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JBqzQ^[n
Utility.log(header+" : "+con.getHeaderField(header)); j EX([J1
else ]Vubz54
break; _^B+Xo@E-
} &HE8O}<>
} FR&RIFy
.F]6uXd
HZm44y$/
public void splitterStop() [x&&N*>N
{ 1Dbe0u
bStop = true; t :_7O7
} wNPZ[V:
|(/"IS]
F"q3p4-<>
} 1)%o:Xy o
9}4L8?2
w-KtxG(
/* QMIQy
**FileAccess.java ,Ya&M@^Z
*//文件访问(定位，写) YC$pT
package NetFox; e'jR<ln|
import java.io.*; 2`z+_DA
E?;W@MJi
6};Sn/8
public class FileAccessI implements Serializable{ ev; &$Hc
8E" .y$AW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a; "+Py
RandomAccessFile oSavedFile; 27MgwX NQ
long nPos; %VdJ<=@
d+bTRnL
ZK;HW
public FileAccessI() throws IOException XhS<GF%
{ OTRTa{TB
this("",0); 8z+ CYeV
} +"C0de|-
t+&WsCN
bZ389dSn
public FileAccessI(String sName,long nPos) throws IOException kqyY:J
{ Jlzhn#5c-
oSavedFile = new RandomAccessFile(sName,"rw"); }/=VnCfU
this.nPos = nPos; qn<~ LxQ
oSavedFile.seek(nPos); ^Ab|\5^3
} Oz+>I^Q
qvT9d7x
cgU7)`0j
public synchronized int write(byte[] b,int nStart,int nLen) Gf"/fpeQx
{ ''V:+@Toh
int n = -1; ak'RV*>mT
try{ ThHK1{87X}
oSavedFile.write(b,nStart,nLen); M]&9Kg3
n = nLen; |ey6Czm
} EZ$m4:{e
catch(IOException e) iQA f
{ 4Fnr8 r8W
e.printStackTrace (); ^@N@gB
} fQv^=DI#
4WNWn#M
$,R|$0B7
return n; mtHw!*
} l<gg5 Zea
* @oAM,@
< B'BlqTS
} 3c6#?<%0`
\}cEHLq
|=SaI%%Be
/* ua2SW(C@
**SiteInfoBean.java n\d-^ml
*/ Jo2:0<VL
package NetFox; s]}P jh8
fHM<6i<C
)O_Y(^+ $
public class SiteInfoBean { :#+VH_%N
fSSDOH!U,
+4)Kc9S#
private String sSiteURL; //Site's URL .i&]VGv
private String sFilePath; //Saved File's Path 7ZN0_Qs
private String sFileName; //Saved File's Name R7vO,kZ6Q
private int nSplitter; //Count of Splited Downloading File )4DF9JpD
xvb5-tK -
oas}8A)
public SiteInfoBean() f 1]1ZOb
{//nSplitter的缺省值为5 }VyDX14j
//default value of nSplitter is 5 xFgY#F
this("","","",5); h_H$+!Nzb
} CY9`ztO*
Qq>M}
)Wgh5C`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2jA-y!(e
{ JEj.D=@[
sSiteURL= sURL; D;m>9{=
sFilePath = sPath; <D=U=5
sFileName = sName; uP<tP:
this.nSplitter = nSpiltter; ZMoN
q*52|?
u>d,6 !
} G/=tC8eX
]x?`&f8i
RH~KaV3
public String getSSiteURL() 06L/i,
{ S)p1[&" M
return sSiteURL; 3s"x{mtH
} A=Dzd/CUO
I)T]}et
iku) otUc
public void setSSiteURL(String value) R0AVAUG
{ <w<&,xM
sSiteURL = value; p"3_u;cN
} e0qU2
D&$%JT'3
dy`K5lC@
public String getSFilePath() !Yd7&#s
{ !bRoNP
return sFilePath; ?X~Keb
} 94\k++kc
?o?~Df&
"1yXOy^2
public void setSFilePath(String value) n}}$-xl
{ ?u/RQ 1
sFilePath = value; 1UT&kD!si
} gWL'Fl}H
$0=f9+@5
:[A>O(
public String getSFileName() }y;s(4
{ %9C_p]P*
return sFileName; .Xqe]cax%
} F=bX\T7
*;5P65:u$>
V]&0"HX2r!
public void setSFileName(String value) <XDYnWz
{ &3#19v7/
sFileName = value; ===M/}r
} \c(R#*0,
rI23e[
/-4rcC
public int getNSplitter() W!MO}0s
{ %L,mj
return nSplitter; L/t'|<m
} iK%%
$t}t'uJ
__O@w.
public void setNSplitter(int nCount) w7+3?'L
{ OXAr..
nSplitter = nCount; AU0pJB'
} _[SW89zk
} @|BaZq,g
Te_%r9P|2
> yk2
/* ?%K7IJ%
**Utility.java VB=$D|Ll
*/ l3[2b Qx
package NetFox; U|ZYoc+](
2SVBuV/R
}M*yE]LL;Z
public class Utility { ZgarxV*
}RvinF:5
-q'G]}
public Utility() X?kw=x{2P
{ KsVN<eR{
7.}Vvg#G
s_:7dD
} yUd>EnQna
qJN!L))
//线程睡眠 Ps<;DE\$f4
public static void sleep(int nSecond) =cz^g^7
{ <MdIQ;I8
try{ oU"!"t
Thread.sleep(nSecond); ~FCkr&Ky3
} >JVdL\3
catch(Exception e) ~$w9L998+
{ zp.-=)D4e
e.printStackTrace (); #O<,
} ;D'6sd"
} $DS|jnpV
meJ%mY
//日志 Pnl+.?
public static void log(String sMsg) xs?Ska,N
{ rlMahY"C
System.err.println(sMsg); we?# Dui
} ,v\^efc:%
|f67aN
x#)CH}J
public static void log(int sMsg) m!#'4
{ skeH~-`M@
System.err.println(sMsg); 9fQ[:Hl"
} I.dS-)Y
} !pTi.3
VB&`S+-
[a201I0 -
/* o|`%>&jP
**TestMethod.java C!X"0]@FA
*/ "($"T v2
package NetFox; -HQ(t
hlKM4JT\
@{V bu
public class TestMethod { $@utlIXA'
y).dw(
ag02=}Q'r
public TestMethod() 2e_m>I
{ ///xx/weblogic60b2_win.exe 2-$O$&s.
try{ X^o0t^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -_[ZRf?^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;]vJ[mi~
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9u0<$UY%
fileFetch.start(); Ie"eqO!
} , ;$SRQ.
catch(Exception e){e.printStackTrace ();} y <] x
qe[P'\]L
H3#rFO"C*
} W6^YFN
o$q})!
Gov]^?^D-
public static void main(String[] args) [x[nTIg
{ ;)Fc@OXN>
new TestMethod(); W @ ?*~
} y?P4EVknM3
} XP%/*am
点击下载更多相关资料