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)); J7.}2
} FS.z lk\D=
for(int i=0;i<nEndPos.length-1;i++) _;*|"e@^
{ >AcpJ|V
nEndPos = nStartPos[i+1]; F12tOSfu*
} QInow2/u
nEndPos[nEndPos.length-1] = nFileLength; ]s lYr8m
} ~'/I[y4t
} h'8w<n+%)
7Gb(&'n
0(9]m)e
//启动子线程 N7lWeF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yKR0]6ahA
for(int i=0;i<nStartPos.length;i++) Pw4j?pv2
{ p_hljgOV
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *|c*/7]<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mPR(4Ol.
nStartPos,nEndPos,i); t >89( k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1c=Roiq
fileSplitterFetch.start(); 7h?yAgDv~
} p{:r4!*L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U].u) g$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); j[/'`1tOe
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \-c8/=
nEndPos = " + nFileLength); $mA+4ISK
// fileSplitterFetch[nPos.length-1].start(); <,~ =o
h-VpX6
q9n0bw^N
//等待子线程结束 )r O`K
//int count = 0; 5BKmp-m
//是否结束while循环 nU"V@_?\
boolean breakWhile = false; *qcL(] Yq
dvUBuY^[
K`PmWxNPh
while(!bStop) 1\d$2N"
{ \FOX#|i)
write_nPos(); W'{q
Utility.sleep(500); lu@#)
breakWhile = true; *"E?n>b
UV>^[/^O
#&\hgsw/T
for(int i=0;i<nStartPos.length;i++) tK&.0)*=
{ )2X ng_,
if(!fileSplitterFetch.bDownOver) X-di^%<
{ ZyqTtA!A
breakWhile = false; JL1%XQ i
break; }z&P^p)R
} Y[8w0ve-g
} J.x>*3<l
if(breakWhile) D5X;hd
break; 5*1wQlL
1r}fnT<
LX.1]T*m`
//count++; ak50]KYo
//if(count>4) u!2.[CV
// siteStop(); lv}U-vK
} "r0z(j
qQR>z
;% *e}w0
System.err.println("文件下载结束！"); 8|[\Tp:;
} maLJ M\C
catch(Exception e){e.printStackTrace ();} :V2j'R,
} {jzN
Pf oAg*
D%LM"p
//获得文件长度 *?oQ6g(Nz
public long getFileSize() v8Ncquv
{ aDa}@-F&a
int nFileLength = -1; &sL5Pt_
try{ Yfy6o6*:
URL url = new URL(siteInfoBean.getSSiteURL()); 8xmw-s)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #&">x7?5
httpConnection.setRequestProperty("User-Agent","NetFox"); yz-IZt(
sZ-]yr\E"
uVqJl{e\
int responseCode=httpConnection.getResponseCode(); ovCk:Vz
if(responseCode>=400) bIizh8d?
{ > 3JU
processErrorCode(responseCode); @u/<^j3Q
return -2; //-2 represent access is error 1G|Q~%cv
} <9bQAyL9
c>K/f7
PKC``+Ki
String sHeader; K_nN|'R-
!U]V?Jpi"
CTtF=\
for(int i=1;;i++) 49 3ik
{ u0$7k9mE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5fb,-`m.
//Utility.log(in.readLine()); ]^gD@].
sHeader=httpConnection.getHeaderFieldKey(i); }M/w 0U0o
if(sHeader!=null) y{ 90A
{ o<-%)#e
if(sHeader.equals("Content-Length")) 'xb|5_D
{ 1L'[DKb'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?w# >Cs(
break; sVkR7 ^KsG
} XrC{{K
} "<6pp4*I
else [RD ^@~x
break; 2Z@<llsi
} aEdFZ
} <-Q0WP_^
catch(IOException e){e.printStackTrace ();} U^Z[6u
catch(Exception e){e.printStackTrace ();} 0s0[U
5HG 7M&_
4PiNQ'*
Utility.log(nFileLength); XoSjYG(>,
Bx&`$lW
0P/A
return nFileLength; $?Aez/
} w0SzK-&
7OtQK`P"A
`P/*x[?
//保存下载信息（文件指针位置） U`6QD}c"s
private void write_nPos() G !1- 20
{ f'FY<ed<w
try{ +nuv?QB/
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6WfyP@f
output.writeInt(nStartPos.length); dGIu0\J\$
for(int i=0;i<nStartPos.length;i++) vkq?z~GA
{ /N%f78 Z
// output.writeLong(nPos); (53dl(L?
output.writeLong(fileSplitterFetch.nStartPos); *"fg@B5
output.writeLong(fileSplitterFetch.nEndPos); @+1E|4L1vf
} RU"w|Qu>pM
output.close(); d@At-Z~M
} NH'RU`U)
catch(IOException e){e.printStackTrace ();} +7 F7Kh
catch(Exception e){e.printStackTrace ();} H.idL6*G
} 'VJMi5Y(-
gn%#2:=pVu
Y1k/ngH
//读取保存的下载信息（文件指针位置） {]<D"x;
private void read_nPos() sQJM 4'8f
{ qsvUJU
try{ 3jS=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +ZRsa`'^
int nCount = input.readInt(); MP}H 5
nStartPos = new long[nCount]; 18[f_0@ #
nEndPos = new long[nCount]; f=K1ZD
for(int i=0;i<nStartPos.length;i++) :VN<,1s9p^
{ Od&M^;BQ
nStartPos = input.readLong(); WKah$l
nEndPos = input.readLong(); ~;eWQwD
} jLQjv
input.close(); {Y/|7Cl0
} eU%5CVH.v
catch(IOException e){e.printStackTrace ();} u/.srK!K
catch(Exception e){e.printStackTrace ();} h*MR5qa
} "[[fQpe4@
tMAa$XrZj
^<E+7
private void processErrorCode(int nErrorCode) klf<=V
{ Dx <IS^>i
System.err.println("Error Code : " + nErrorCode); !FSraW2
} &]LwK5SR
=R>Sxaq
yQi|^X~?$
//停止文件下载 l*v([@A\
public void siteStop() =rBFMTllM
{ IN%>46e`
bStop = true; }2NH>qvY
for(int i=0;i<nStartPos.length;i++) t*qA.xc6
fileSplitterFetch.splitterStop(); vhL&az
^F"*;8$
*<Ddn&_
} oVq@M
} DGd&x^C
//负责部分文件的抓取 L//sJe
**FileSplitterFetch.java 5ef&Ih.3
*/ mlVv3mVyR<
package NetFox; 8fe"#^"sR
g u|;C
e< CPaun
import java.io.*; "^XN"SUw
import java.net.*; Q}=RG//0*
b8]oI"&G
Ro<!n>H
public class FileSplitterFetch extends Thread { eGTK^p
|iwTzlt*#
g$ 2M|Q
String sURL; //File URL .R gfP'M
long nStartPos; //File Snippet Start Position Iyc')\W&
long nEndPos; //File Snippet End Position mefmoZ
int nThreadID; //Thread's ID `PW=_f={
boolean bDownOver = false; //Downing is over he+[
boolean bStop = false; //Stop identical #>- rKv.A
FileAccessI fileAccessI = null; //File Access interface 6VE >$`m
<oXsn.'\
i3%~Gc63
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~qqtFjlG^
{ J.nVEqLZ
this.sURL = sURL; xlwsZm{V
this.nStartPos = nStart; 'I<j`)4`d
this.nEndPos = nEnd; iit`'}+U
nThreadID = id; N)!v-z,k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [e}]K:
} ky~x4_y5
&(rd{j/*
Dq?2mXOqD
public void run() SRD&Uf0M
{ Rke:*(p*n;
while(nStartPos < nEndPos && !bStop) ^=W&p%Y(!
{ TdE_\gEo/R
=#V11j
Z|/):nVP7
try{ F4&N;Zm2
URL url = new URL(sURL); SW; bE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]rNfr-
httpConnection.setRequestProperty("User-Agent","NetFox"); &*yve}su
String sProperty = "bytes="+nStartPos+"-"; }fCM_w
httpConnection.setRequestProperty("RANGE",sProperty); 5rWRE-
Utility.log(sProperty); = ]@xXVf/
)/ZSb1!
V")Q4h{
InputStream input = httpConnection.getInputStream(); c:6w >:
//logResponseHead(httpConnection); qnS7z%H8
IY19G U9
9@1W=sl
byte[] b = new byte[1024]; ~>C>LH>8
int nRead; kp6x6%{K\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M[{Cy[ta
{ zh.c_>jS
nStartPos += fileAccessI.write(b,0,nRead); lET)<V(Y
//if(nThreadID == 1) P X0#X=$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b5|p#&YK~
} amSyGQ2
)aC+qhh
JdRs=#X
Utility.log("Thread " + nThreadID + " is over!"); >'jM8=o*Ax
bDownOver = true; /iN\)y#u1
//nPos = fileAccessI.write (b,0,nRead); sXa8(xc
} 64vSJx>u
catch(Exception e){e.printStackTrace ();} [>:gwl _\
} 3?XLHMxW
} U .Od
bGJUu#
l xfdJNb
//打印回应的头信息 #TWc` 8
public void logResponseHead(HttpURLConnection con) nGbrWu]w
{ sy?>e*-{
for(int i=1;;i++) !kcg#+s91
{ B1M/5cr.
String header=con.getHeaderFieldKey(i); FSmi.7
if(header!=null) @Y,F&8a$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Hj\~sR$L-
Utility.log(header+" : "+con.getHeaderField(header)); aOHCr>po,
else ,$]q2aL
break; N93E;B
} _tk5?9Ykn
} vck$@3*
nAg(lNOWN
zoJ;5a.3B
public void splitterStop() UIl_&|
{ TUaK:*x*
bStop = true; zEB1Br,
} }j?S?=;m=
zvf]}mNx
;Wa{q.)
} E5(Y*m!
\zi3.;9|;
^ ?=K)
/* nsT|,O
**FileAccess.java #$w#"Nr9k
*//文件访问(定位，写) O0~d6Ba
package NetFox; 3ngLEWT
import java.io.*; sb @hGS
3CE8+PnT
^kr)U8
public class FileAccessI implements Serializable{ g#4gGhI
+V@=G &Ou0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~Z]vr6?$h
RandomAccessFile oSavedFile; VTWE-:r
long nPos; `0i3"06lr
)DmiN^:
B@]7eVo
public FileAccessI() throws IOException lX*;KHT)
{ swlWe}1
this("",0); ,}tdfkZFYl
} o"FiM5L^.
Zir`IQ$
SR& mHI-f0
public FileAccessI(String sName,long nPos) throws IOException skz]@{38
{ F}]_/cY7B
oSavedFile = new RandomAccessFile(sName,"rw"); Q:O>kCDV
this.nPos = nPos; (U_Q7hja?
oSavedFile.seek(nPos); FIjET1{
} @q/1m~t
pK9^WT@
2?T:RB}
public synchronized int write(byte[] b,int nStart,int nLen) X u):.0I
{ dz|*n'd
int n = -1; pq3 A%|
try{ i)L:VkN
oSavedFile.write(b,nStart,nLen); pRvs;klf
n = nLen; ;8iL,^.A
} ~n^G<iXLp
catch(IOException e) 0f%:OU5Y
{ ;_/q>DR>,3
e.printStackTrace (); 8 %j{4$
} o0G`Xn
9.zQ<k2
`4H9f&8(
return n; A_Iu*pz^^
} 51 0XDl~b
A{I a21T7
8 tygs
} 'd^gRH<z
9JV 3
EQJ_$6
/* 0;v~5|r
**SiteInfoBean.java ^<\} Y
*/ !t Oky
package NetFox; g&3#22z
uq4sbkP
SrtVoe[
public class SiteInfoBean { qW~R-g]
$p3Wjf:bH
5u_4lNJ&
private String sSiteURL; //Site's URL Gd-.E7CH!
private String sFilePath; //Saved File's Path RLz`aBT
private String sFileName; //Saved File's Name ^D;D8A.
private int nSplitter; //Count of Splited Downloading File 6b]d|
bmVgTm&
2nU NI U
public SiteInfoBean() iW@Vw{|i I
{//nSplitter的缺省值为5 1m`tqlFU9
//default value of nSplitter is 5 7~ese+\smG
this("","","",5); o,Zng4NY
} i!W8Q$V
S@xsAib0J
pLQSG}N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )L<?g!j~
{ o9LD6$
sSiteURL= sURL; 1O2h9I$bk
sFilePath = sPath; %DRy&k/T
sFileName = sName; 2^bpH%
this.nSplitter = nSpiltter; pR6A#DgB
; G59}d p~
^wF@6e7/&
} <W51oO
^q&wITGI
)fMX!#KP
public String getSSiteURL() @=0r3
{ `Kc %S^C'
return sSiteURL; gQh Ccv
} reM
cF&h$4-
UW/3{2
public void setSSiteURL(String value) Ac!&j=ZE
{ +%#MrNM'
sSiteURL = value; l?JO8^Nn
} jqGo-C~
0"^oTmQN
9U<)_E<y
public String getSFilePath() SZ2q}[o`R
{ }C{}oLz
return sFilePath; vYSetAdv
} d0A\#H_&
\ ~LU 'j
sK 1m9
public void setSFilePath(String value) R'9@A\7#
{ *%N7QyO`I
sFilePath = value; OHP3T(Q5
} {|5$1v
?]\W8)
< k+fKl
public String getSFileName() e.}3OK
{ *mQDS.'AB@
return sFileName; RC8)f8n
} ^KZAYB9C
*)NR$9lGv
{rb-DB-/5M
public void setSFileName(String value) <Id1:
{ F/h:&B:;
sFileName = value; )pS_+ZF
} V^ fGRA
{FJX
7zg)h
public int getNSplitter() iVq#aXN
{ {wpMg
return nSplitter; g8+4$2`ny
} _PyW=Tj
5"}y\
Lf; ta
public void setNSplitter(int nCount) &6\r
{ V|3yZ8lE
nSplitter = nCount; :^H9W^2
} ^/%o%J&Hz
} 17i<4f#
z<oE!1St
TRk ?8
/* co<2e#p;
**Utility.java ^fE\S5P
*/ yp[<9%Fi
package NetFox; 'z +$3\5L
ez^*M:K
+ 9\:$wMN
public class Utility { 7cUR.PI#Q
%UUp=I
Ok}{jwJ%W;
public Utility() FI?gT
{ %Ye)8+-
b:FEp'ZS
`'xQ6Sy
} B?$01?9V
U^[cYTG
//线程睡眠 YW?7*go'Z
public static void sleep(int nSecond) {k_ PMl0G
{ o%V @D'w
try{ [!J @a
Thread.sleep(nSecond); P\q<d
} ch0oFc$
catch(Exception e) :(bdI]
{ 3{NaZIk
e.printStackTrace (); DA+A >5/
} Q$xa
} Em~7D]Y
V17>j0Ev$W
//日志 9tzoris[~
public static void log(String sMsg) }zkL[qu;
{ c!\.[2n
System.err.println(sMsg); iUeV5cB
} qs6Nb'JvQR
935-{h@k
MB]#%g&
public static void log(int sMsg) ~/j$TT"
{ 4ss&'h
System.err.println(sMsg); &Pu+(~'Q
} b$dJ?%W
} 5nMkd/
h^o+E2<]
&K5C=]4
/* Y%78>-2L
**TestMethod.java y2z{rd
*/ qpb/g6g
package NetFox; cm@jt\D
]$m#1Kj
" Sc5qG
public class TestMethod { Y3vX)D}
1YJ_1VJ
DNm(:%)0
public TestMethod() u iBl#J Q
{ ///xx/weblogic60b2_win.exe |7svA<<[
try{ BCBEX&0hk{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X|X4L(i
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FovE$Dj]
SiteFileFetch fileFetch = new SiteFileFetch(bean); +<pVf%u5
fileFetch.start(); nGq]$h
} Ef2Yl
catch(Exception e){e.printStackTrace ();} y]yine
{V}t'x`4c
y=[gQJ6~r
} KKLR'w,A>
]YCPyc:
W*YxBn4
public static void main(String[] args) lemVP'cn
{ &}vR(y*#c
new TestMethod(); h7bPAW=(
} EfFz7j&X
} Yuwc$Qp)
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