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)); ($W9 ?
} s_Dl8O4u
for(int i=0;i<nEndPos.length-1;i++) uR)@v^$FE
{ 6U+#ADo
nEndPos = nStartPos[i+1]; "3j0)
} b8v$*{
nEndPos[nEndPos.length-1] = nFileLength; f(n{7
} !Xj m h$F
} d=4MqX r
puqH%m+u
3iEcLhe"4
//启动子线程 4 |5ekwk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $uLzC]
for(int i=0;i<nStartPos.length;i++) MB |(,{S
{ aQ~x$T|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q-8 GD7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ga~vQ7I_
nStartPos,nEndPos,i); cq9Q7<&MF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #uXOyiE
fileSplitterFetch.start(); *<A;jP
} <WbD4Q<3?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UZAWh R
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7R2)Klt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eO9nn9lql
nEndPos = " + nFileLength); X)&Z{ V>
// fileSplitterFetch[nPos.length-1].start(); !eTS PM
Ph%s.YAZ~
z~Pmh%b
//等待子线程结束 8\V-aow
//int count = 0; i ('EBO
//是否结束while循环 ?\pE#~m
boolean breakWhile = false; RU>vnDaC
1Ev+':%
\S@A /t6pa
while(!bStop) 4*,q1yK
{ JZnWzqFw
write_nPos(); QJE-$ :
Utility.sleep(500); 'OihA^e
breakWhile = true; SmLYxH3F
f:Ja
{pg@JA
for(int i=0;i<nStartPos.length;i++) ~^C7(g )
{ 7w$R-Y/E
if(!fileSplitterFetch.bDownOver) 4>Y\2O?**
{ w${=dW@K
breakWhile = false; *Fc&DQT(
break; ,qHG1#^
} H.mG0x`M"E
} :58'U|
if(breakWhile) Sp )}
break; ri;M7rg`.{
5q#|sVT7R
Y_B 4s-
//count++; Xda<TX@-
//if(count>4) (R}X(u
// siteStop(); eEh0T%9K
} Ny'v/+nQ
MB 5[Js|
;X6y.1N~
System.err.println("文件下载结束！"); -]A#G`'
} b?NeSiswn
catch(Exception e){e.printStackTrace ();} Ft rw3OxN
} 7jbmw<d)9
I}v#r8'!
e;'T?&t
//获得文件长度 kZ}u
public long getFileSize() 9GwsQ \
{ 15:@pq\
int nFileLength = -1; nQHd\/B
try{ jq)|7_N
URL url = new URL(siteInfoBean.getSSiteURL()); Kx+Bc&X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @R&D["!
httpConnection.setRequestProperty("User-Agent","NetFox"); 5; [|k$ v
E|;5Z*
({VBp[Mh
int responseCode=httpConnection.getResponseCode(); tQaCNS$=
if(responseCode>=400) ,b(S=r
{ -b}S3<15@
processErrorCode(responseCode); I{I [N &N
return -2; //-2 represent access is error @e0skc
} \=V[ba:q
.6F3;bg R7
uW9M&"C~
String sHeader; b[;3KmUB
J\$l3i/I
==Mi1Q#5C
for(int i=1;;i++) UjOhaj "h
{ :fVMM7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 786_QV
//Utility.log(in.readLine()); ]q7 LoH'S
sHeader=httpConnection.getHeaderFieldKey(i); MxEAs}MDv
if(sHeader!=null) o>-v?Ug
{ :_a]T-GL
if(sHeader.equals("Content-Length")) cloSJmUlQ
{ tB=D&L3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TK/'=8
break; &E riskI
} Z"|P(]A
} 7XWBI\SW
else 7QiCZcb\
break; H!.D2J
} kz;_f
} akW3\(W}
catch(IOException e){e.printStackTrace ();} UZ\*]mxT
catch(Exception e){e.printStackTrace ();} k)K-mD``U
3|+f si)x
xhkWKB/7
Utility.log(nFileLength); i;hc]fYb=K
IPR tm!
<I%9O:R
return nFileLength; e_c;D2'F
} 4<Sa,~4
.`&/QiD
RjGB#AK
//保存下载信息（文件指针位置） nlebFDb7
private void write_nPos() )uid!d
{ ](=wlq)
try{ 1:xnD
output = new DataOutputStream(new FileOutputStream(tmpFile)); Sj{ia2AE_
output.writeInt(nStartPos.length); _7#tgZyv
for(int i=0;i<nStartPos.length;i++) N.{jM[\F
{ d[]p_oIQq
// output.writeLong(nPos); yD"0=\
output.writeLong(fileSplitterFetch.nStartPos); ,#bb8+z&p
output.writeLong(fileSplitterFetch.nEndPos); $'knK<
} !b]2q%XM
output.close(); WTD49_px
} q|u8CX
catch(IOException e){e.printStackTrace ();} G4`Ut1g^
catch(Exception e){e.printStackTrace ();} lgonR
} +|?|8"Qg
SE^b0ZV*x
`N,Vs n"
//读取保存的下载信息（文件指针位置） uPFHlT
private void read_nPos() SCurO9RN
{ 27a*H1iQ
try{ ;>Ca(Y2M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r6n5Jz
int nCount = input.readInt(); ^b"bRQqm
nStartPos = new long[nCount]; pYfV~Q^3
nEndPos = new long[nCount]; nQ642i%RQ
for(int i=0;i<nStartPos.length;i++) Y%/ YFO2vb
{ Be{/2jU%
nStartPos = input.readLong(); {M@@)27gW
nEndPos = input.readLong(); g8,?S6\nMz
} w*:GM8=6
input.close(); NuD[-;N]
} e?!L}^f6X
catch(IOException e){e.printStackTrace ();} B.YMP;7>
catch(Exception e){e.printStackTrace ();} ~ThVap[*
} Ns2,hQFc
v_z..-7Dq+
_hy{F%}
private void processErrorCode(int nErrorCode) ';b3Mm #
{ Uvh~B^6
System.err.println("Error Code : " + nErrorCode); CZyz;Jtk
} D1X4|Q*SK
*#1y6^
NfTCpA
//停止文件下载 3I"NI.>*
public void siteStop() zLsb`)!
{ E.J0fwyT
bStop = true; <&5m N
for(int i=0;i<nStartPos.length;i++) skIiJ'db
fileSplitterFetch.splitterStop(); %kh#{*q$
s.yq}Q
1~2R^#rm
} 5LX8:~y
} D<U 9m3
//负责部分文件的抓取 oZvA~]x9\
**FileSplitterFetch.java +VCo$o
*/ 4^DVW*OiI
package NetFox; y=AsgJ
BXg!zW%+
bLgL0}=n
import java.io.*; (j' {~FB
import java.net.*; 90/vJN
{p`mfEE(
SY-ez91
public class FileSplitterFetch extends Thread { i:o}!RZ>
{L@+(I
A4G,}r *n
String sURL; //File URL X^}A*4j
long nStartPos; //File Snippet Start Position AF^T~?t
long nEndPos; //File Snippet End Position ]^=|Zd-
int nThreadID; //Thread's ID 9W!8gCs
boolean bDownOver = false; //Downing is over fb\DiKsW
boolean bStop = false; //Stop identical 0YzsA#yv
FileAccessI fileAccessI = null; //File Access interface (1CJw:
+TC1nkX
5Go0}'*%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B?LXI3sQZ
{ s/ M7Zl
this.sURL = sURL; 0$6*o}N%
this.nStartPos = nStart; 2-++i:, g
this.nEndPos = nEnd; CRFCqmevR
nThreadID = id; )kYOHS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \PpXL*.
} '>@4(=I
AoBoFZLl3
!tEe\K\e
public void run() m0|K#^
{ G.g|jP'n
while(nStartPos < nEndPos && !bStop) x?"#gK`3;
{ n~tqO!q
fb.J$fX
[*8Y'KX <
try{ 845 W>B
URL url = new URL(sURL); ~-TOsRvxR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fN-Gk(Ic
httpConnection.setRequestProperty("User-Agent","NetFox"); mEFw|M{
String sProperty = "bytes="+nStartPos+"-"; X7aYpt;
httpConnection.setRequestProperty("RANGE",sProperty); !}y1CA
Utility.log(sProperty); GWsd| kxU
B^fT>1P
uWjN2#&,
InputStream input = httpConnection.getInputStream(); DAdYg0efex
//logResponseHead(httpConnection); B**Nn!}0
nnwJYEi
c%z'xM
byte[] b = new byte[1024]; BOvF)4`
int nRead; o}8I_o&]U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u%u&F^y
{ @w\I qr
nStartPos += fileAccessI.write(b,0,nRead); $ rUSKm#
//if(nThreadID == 1) gAt~?HvW6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gZO&r#
} ~.^AL}zm_
7(bQ}mHl\
xzsdG?P
Utility.log("Thread " + nThreadID + " is over!"); g # S0V
bDownOver = true; 1l5JP|x
//nPos = fileAccessI.write (b,0,nRead); `&!k!FZY*
} 4zjs!AK%
catch(Exception e){e.printStackTrace ();} Ipe n
} Y9Z]i$qS&k
} "Y;}GlE
`zA#z />
u.,Q4u|!
//打印回应的头信息 j.m(ltGh
public void logResponseHead(HttpURLConnection con) z.36;yT/
{ Es!Q8.
for(int i=1;;i++) a~PK pw2%
{ ;AX8aw,
String header=con.getHeaderFieldKey(i); }^xE|~p
if(header!=null) yVX8e I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4;<ut$G
Utility.log(header+" : "+con.getHeaderField(header)); s?2$ue&-f
else )1 m">s4
break; [;A[.&6
} lk3=4|?zsE
} MSw$_d
]fBUT6
#wY0D_3@1
public void splitterStop() M}O}:1Par
{ zmI]cD@G
bStop = true; v6GPS1:a
} hI},~af
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b[I8iSkfi
} [sF(#Y:I
cPDQ1qre!
58 bCUh#uw
/* I_1e?\
**FileAccess.java i,IB!x
*//文件访问(定位，写) b2,!g }I
package NetFox; Djq!P
import java.io.*; |~!U4D\
,m_WR7!$E
T4)fOu3]
public class FileAccessI implements Serializable{ (wRgus
!-<p,z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {vEOn-(7
RandomAccessFile oSavedFile; qpIC{'A.
long nPos; F+m }#p
3ZEB
2*w0t:Yxe
public FileAccessI() throws IOException z2_6??tS/c
{ UT0){%2@
this("",0); 5"XC$?I<}
} El\%E"Tk%
6AG`&'"
'k;rH!R
public FileAccessI(String sName,long nPos) throws IOException |a1{ve[
{ $odso;Hn
oSavedFile = new RandomAccessFile(sName,"rw"); b 5yW_Ozdh
this.nPos = nPos; KlRr8G!Z
oSavedFile.seek(nPos); MZ+^-@X
} }>)[<;M>%
J'$>Gk]
<sK4#!K
public synchronized int write(byte[] b,int nStart,int nLen) Mmpfto%i
{ 1`ayc|9BR
int n = -1; jCbV,0)^
try{ q`-;AG|xF
oSavedFile.write(b,nStart,nLen); C8 \5A8c
n = nLen; ,]bB9tid
} sMu] /'7
catch(IOException e) }gJ(DbnV
{ QQWadVQo
e.printStackTrace (); lpz2 m\
} '!/<P"5t
J8mdoVt
Z&;uh_EC
return n; sI{ M
} 9eH$XYy
5[c^TJ3
}Y;K~J
} ")d`dj\o
1t)il^p4[;
Na:w]r:y
/* }GeSu|m(
**SiteInfoBean.java : |>Gc39`t
*/ =Xo =Qcr
package NetFox; V4_=<W
|`.([2
~]QHk?[wc
public class SiteInfoBean { #{?qNl8F*J
ZMel{w`n
ax(c#
private String sSiteURL; //Site's URL _H5o'>=
private String sFilePath; //Saved File's Path R6]Gk)5
private String sFileName; //Saved File's Name 8P|D13- Q
private int nSplitter; //Count of Splited Downloading File DQr Y*nH
=>_\fNy
)c)vTZy
public SiteInfoBean() 9Gnc9_]I;W
{//nSplitter的缺省值为5 Y\No4w ^|d
//default value of nSplitter is 5 A<??T[
this("","","",5); "vOwd.(?N
} c-(UhN3WG
sVOyT*GY
R^Y <RI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |'B7v i)
{ ?!` /m|"
sSiteURL= sURL; Sy0$z39
sFilePath = sPath; TA4!$7b$
sFileName = sName; =`H@%
this.nSplitter = nSpiltter; OWg(#pZk
oYH^_V
\RC'XKQ*n
} !WQ-=0cm
{+Rog/;S'
U_I5fK=
public String getSSiteURL() ^LoUi1j
{ kY-N>E:
return sSiteURL; ]QlwR'&j/n
} <^5Z:n!q
P*3BB>FO
HMh"}I2n
public void setSSiteURL(String value) #."-#"0
{ $Avjnm
sSiteURL = value; B#Vz#y
} 7o#I,d~
*Doa*wQ
-z)n?(pftm
public String getSFilePath() '!!CeDy
{ Ch<[l8;K
return sFilePath; Oi8.8M
} 3KlbP
A>o*t=5
+M\`#i\g>
public void setSFilePath(String value) dMv=gdY
{ iTgt}]L
sFilePath = value; keL&b/@
} 4%>$-($
k@RDvn
R;&AijS8
public String getSFileName() _=F=`xu
{ yerg=,$_i
return sFileName; Jh,]r?Bd
} 96( v
e>+i>/Fn{h
cQy2"vtU
public void setSFileName(String value) Lt?lv2k=L
{ ls\WXCH
sFileName = value; tkeoNuAM
} /R]U}o^/(%
ayR-\mZ
GfoLae
public int getNSplitter() snE8 K}4
{ bnf'4PAt
return nSplitter; s~ a"4~f
} &Cr:6W@A
89pEfl j2
2=,lcWr
public void setNSplitter(int nCount) _|kxY'_[8
{ ]7W&JKmA&
nSplitter = nCount; w'Y7IlC
} +"\sc;6m.
} N)uSG&S:
DR5\45v
s4X>.ToMC
/* >)fi^
**Utility.java !JHL\M>A5
*/ rK'L6o
package NetFox; ?PuBa`zDE
}eCw6
:C(=&g<]D
public class Utility { RIWxs Zt
dyz2.ZY~2
.F98G/s
public Utility() +nrbShV
{ M8MRoA6F
~ (|5/ p7t
!`Fxa4i>
} EU2$f
,k +IPkN+
//线程睡眠 p|X"@kuseO
public static void sleep(int nSecond) h]IxXP?h[
{ a#cCpE
try{ t6bV?nc
Thread.sleep(nSecond); F&4rO\aC"/
} -]0OKE&
catch(Exception e) Jj; L3S
{ f%is~e~wc
e.printStackTrace (); }*M6x;t
} kvL=> A
} .[]r}[lU
l5S aT,%
//日志 ;km`P|<U
public static void log(String sMsg) %f&/E"M
{ Q:2>}QgX}
System.err.println(sMsg); 5bRJS70M
} b o6d)Q
3@etRd;]Kr
R5N%e%[
public static void log(int sMsg) VACQ+
{ t|w_i-&b,
System.err.println(sMsg); Vh'P&W?[
} ak7bJ~)X=
} }n]Ng]KM`
66g9l9wm(
>nJ\BPx
/* {DV_*5
**TestMethod.java A=$04<nP8!
*/ T;Lkaxsn
package NetFox; ui<N[
&W|[r(
a!zz6/q[
public class TestMethod { +5w))9@
4X!/hI=jq
$.Qkb@}
public TestMethod() d6Ht2
{ ///xx/weblogic60b2_win.exe 2i)^!c
try{ =ElO?9&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ansk,$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4V{:uuI;f
SiteFileFetch fileFetch = new SiteFileFetch(bean); ty8q11[8
fileFetch.start(); GoJ.&aH $
} j b!x:
catch(Exception e){e.printStackTrace ();} q_MPju&*
fW{(lPx
G4Q[Th
} ^%d\qd`
pd:WEI ,
B al`y
public static void main(String[] args) 4.k0<
{ ?qmRbDI
new TestMethod(); =J18eH!]
} 6gL#C&
} `"Jj1O@
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