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)); ~A\GT$
} ZP(f3X@
for(int i=0;i<nEndPos.length-1;i++) HAa;hb
{ u ,KD4{!
nEndPos = nStartPos[i+1]; A*\.NTM
} 5?x>9Ca
nEndPos[nEndPos.length-1] = nFileLength; ,5h)x"s
} iUN Ib
} aht[4(XH5
cz8T
NPp;78O0[
//启动子线程 'd9INz.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8]9%*2"!
for(int i=0;i<nStartPos.length;i++) ;>Ib^ov
{ gDpVeBd[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4\iOeZRf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H*PSR
nStartPos,nEndPos,i); %iQD /iT5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %WjXg:R
fileSplitterFetch.start(); [DI+~F
} J| w>a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ds<2I,t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |IzPgC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8<QdMkI
nEndPos = " + nFileLength); <eWf<
// fileSplitterFetch[nPos.length-1].start(); bKMy|_
m+]K;}.}R
Fj2BnM3#
//等待子线程结束 ,s"^kFl
//int count = 0; s;ls qQk
//是否结束while循环 H&-zZc4\
boolean breakWhile = false; X}Ai-D
[M=7M}f;
QTk}h_<u
while(!bStop) m;GCc8
{ _l89
write_nPos(); +V{kb<P
Utility.sleep(500); *XIF)Q=<>
breakWhile = true; i9,geQ7d
4O^xY 6m
1~NT.tY
for(int i=0;i<nStartPos.length;i++) n{argI8wF
{ k_rt&}e+Gi
if(!fileSplitterFetch.bDownOver) Swig;`
{ -cAo@}v
breakWhile = false; tEvut=k'
break; *0Skd
} iP ->S\
} .WZ^5>M-
if(breakWhile) Ga^"1TZ x
break; #lL^?|M
KJ)k =mJ
8V`WO6*
//count++; W}@c|d $`
//if(count>4) #A JDWelD
// siteStop(); -=)H{
} y51e%n$
s<<ooycBrQ
1#< '&Lr
System.err.println("文件下载结束！"); ^@s1Z7
} $r@zs'N
catch(Exception e){e.printStackTrace ();} E Nhl&J
} f@wquG'
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|4;Fd9q^m
//获得文件长度 1Y\DJ@lh
public long getFileSize() wDal5GJp
{ `ts$(u.w
int nFileLength = -1; PR#exm&
try{ FrfM3x6UM
URL url = new URL(siteInfoBean.getSSiteURL()); |6sp/38#p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >* f-Wde
httpConnection.setRequestProperty("User-Agent","NetFox"); 5H<m$K4z
[ )Iv^ U9
'}53f2%gKa
int responseCode=httpConnection.getResponseCode(); ;PF<y9M
if(responseCode>=400) )l C)@H}
{ %S960
processErrorCode(responseCode); P^~yzI
return -2; //-2 represent access is error & p
} 99e.n0
g[' ^L+hd
WUn]F~Lt
String sHeader; u5`u>.!
EIP/V
xX&+WR
for(int i=1;;i++) fgp]x&5Q
{ l`lk-nb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cJ=6r :
//Utility.log(in.readLine()); q_[o"wq/
sHeader=httpConnection.getHeaderFieldKey(i); MS~(D.@ZS
if(sHeader!=null) #4<SAgq
{ *SJ_z(CZm
if(sHeader.equals("Content-Length")) tKOmoC
{ zZPO&akB"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {H>gtpVy
break; @1roe G
} ,wb:dj-
} {BN#h[#B{
else t\dN DS
break; #jvtUS\
} yLvDMPj
} EeE7#$l
catch(IOException e){e.printStackTrace ();} `KoV_2|
catch(Exception e){e.printStackTrace ();} zFfr.g;L
VPJElRSH
BA:VPTZq
Utility.log(nFileLength); y%cP1y)
R`qFg/S
2*& ^v
return nFileLength; ,]F,Uu_H7
} WaRw05r
W' VslZG
tCH!my_
//保存下载信息（文件指针位置） 3qC}0CP*
private void write_nPos() AO4U}?
{ 1v27;Q<+Q
try{ Ty?cC**
output = new DataOutputStream(new FileOutputStream(tmpFile)); Tx# Mn~xD
output.writeInt(nStartPos.length); D%pF;XY
for(int i=0;i<nStartPos.length;i++) (mpNcOY<D
{ %$Tji
// output.writeLong(nPos); eu-*?]&Di
output.writeLong(fileSplitterFetch.nStartPos); pz}.9 yI8
output.writeLong(fileSplitterFetch.nEndPos); Se}c[|8
} e#8Q L
output.close(); H/ HMm{4
} A|4[vz9>H
catch(IOException e){e.printStackTrace ();} A}9`S6@@
catch(Exception e){e.printStackTrace ();} v@L;x [Q
} K($Npuu]
$7ZX]%<s
$qnZl'O>
//读取保存的下载信息（文件指针位置） QA`sx
private void read_nPos() QZ
{ B~ GbF*j
try{ Wqw1J=]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %ntRG!
int nCount = input.readInt(); D/&o&G96
nStartPos = new long[nCount]; kgP0x-Ap
nEndPos = new long[nCount]; e X|m
for(int i=0;i<nStartPos.length;i++) AQvudx)@"
{ ]h+j)J}[A
nStartPos = input.readLong(); +I|vzz`ZVr
nEndPos = input.readLong(); V b?oJhR
} 14yv$,
input.close(); ^6V[=!& H
} 8Fu(Ft^9
catch(IOException e){e.printStackTrace ();} ea 'D td
catch(Exception e){e.printStackTrace ();} SY\ gXO8k
} f.$af4 u
+a+Om73B2
'-~~-}= sJ
private void processErrorCode(int nErrorCode) l'_r:b
{ @qAS*3j
System.err.println("Error Code : " + nErrorCode); fIU#M]Xx
} VY4yS*y
sDlO#
Kw ]=
//停止文件下载 sUQ@7sTj
public void siteStop() %dVZ0dl
{ VpDbHAg
bStop = true; <PH#[dH
for(int i=0;i<nStartPos.length;i++) 5U$0F$BBp
fileSplitterFetch.splitterStop(); +[mk<pQ
m;QMQeGz
Kn1a>fLaJ_
} !Wnb|=j
} oZ|\vA%4^
//负责部分文件的抓取 !%c\N8<>GD
**FileSplitterFetch.java <0!):zraS
*/ %>{0yEC
package NetFox; ^<2p~h0 \
h S&R(m
/a4{?? #e
import java.io.*; 64tvP^kp
import java.net.*; M .mfw#*
D'Q\za
@\#td5'
public class FileSplitterFetch extends Thread { 83#mB:^R
zK@@p+n_#.
eng'X-x
String sURL; //File URL jNk%OrP]
long nStartPos; //File Snippet Start Position i8]S:49
long nEndPos; //File Snippet End Position MQ8J<A Pf-
int nThreadID; //Thread's ID |CRn c:
boolean bDownOver = false; //Downing is over *$g-:ILRuZ
boolean bStop = false; //Stop identical Y$@?.)tY
FileAccessI fileAccessI = null; //File Access interface "4{r6[dn
wf<M)Rs|
.?$gpM?i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4.t-i5
{ DB,J3bm
this.sURL = sURL; cbTm'}R(G
this.nStartPos = nStart; PdWx|y{%
this.nEndPos = nEnd; .$vK&k
nThreadID = id; jse&DQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 PEZ!n.'S
} C,4e"yynb
4o[{>gW
Nj/ x. X
public void run() xJ.M;SF4
{ nU7[c| =
while(nStartPos < nEndPos && !bStop) O:K2Y5R?B
{ 0o&5]lEe
^iV)MTT
Zj'9rXhrM1
try{ j0q&&9/Jj
URL url = new URL(sURL); vnuN6M{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); & 1f+,
httpConnection.setRequestProperty("User-Agent","NetFox"); LrpM\}t
String sProperty = "bytes="+nStartPos+"-"; 2D5StCF$O
httpConnection.setRequestProperty("RANGE",sProperty); |`FY1NN
Utility.log(sProperty); 'LDQgC*%
rYk0 ak
;!Fn1|)
InputStream input = httpConnection.getInputStream(); p5*EA x
//logResponseHead(httpConnection); x]j W<A
4CTi]E=H{
6_B]MN!(
byte[] b = new byte[1024]; $%f&a3#
int nRead; I7]8Y=xf
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gs`q6f%(
{ .T`%tJ-Em
nStartPos += fileAccessI.write(b,0,nRead); <1TAw.
//if(nThreadID == 1) &UFZS94@r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M<&= S
} (/$^uWj
}x,S%M-
xoME9u0x4
Utility.log("Thread " + nThreadID + " is over!"); Q+{n-? :
bDownOver = true; .e-#yET
//nPos = fileAccessI.write (b,0,nRead); 'Pbr v
} 8eRLy/`gd
catch(Exception e){e.printStackTrace ();} Q,Eo mt
} BTxrp
} m]&SNz=
3XNCAb2
N2o7%gJw
//打印回应的头信息 &7s.`
public void logResponseHead(HttpURLConnection con) @2#lI
{ R.3q0yZ wF
for(int i=1;;i++) -nwypu
{ qe\5m.k
String header=con.getHeaderFieldKey(i); A@u@ift
if(header!=null) 7xR\kL.,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cZ3v=ke^
Utility.log(header+" : "+con.getHeaderField(header)); J .<F"r>
else B)UZ`?>c
break; \b>]8Un"
} J[kTlHMD
} 1Z&(6cDY8M
XK vi=0B
wuo,kM
public void splitterStop() 7j{?aza
{ =EsavN
bStop = true; Uw:"n]G]D?
} l+b~KU7~l
}QmqoCAE~m
GA.8@3
} z(~_AN M4,
&5R&k0i r
K)P%;X
/* Tj- s4x
**FileAccess.java Alq(QDs
*//文件访问(定位，写) C_Wc5{
package NetFox; D m9sL!
import java.io.*; y)<q/
(tO\)aS=
phz&zlD
public class FileAccessI implements Serializable{ Tsx>&WC
4&iCht =
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 qJw_
RandomAccessFile oSavedFile; *K;~!P
long nPos; o !7va"
Ea=P2:3*
6MI8zRX
public FileAccessI() throws IOException Bbp|!+KP{(
{ ##ANrG l
this("",0); @%SQFu@FJ
} D&zle~" J
T^q 0'#/
wKHBAW[i]
public FileAccessI(String sName,long nPos) throws IOException 3gf1ownC
{ zW nR6*\
oSavedFile = new RandomAccessFile(sName,"rw"); ?h2}#wg
this.nPos = nPos; 'B}qZCy W
oSavedFile.seek(nPos); WF"k[2
} _vZOZKS+
,u!sjx
y+;|Fz
public synchronized int write(byte[] b,int nStart,int nLen) [/ZO q
{ 2T`!v
int n = -1; 3uMy]HUQ
try{ dqAw5[qMJ
oSavedFile.write(b,nStart,nLen); l;V173W=&
n = nLen; o"SMbj
} H)&R=s
catch(IOException e) jh$='Gn
{ 92-I~ !d
e.printStackTrace (); rLT!To
} h7@6T+#WoT
A)~6Im
QCJM&
return n; xLn%hxm?,
} (iGTACoF
$ulOp;~A%
y?!"6t7&
} ET >](l9
=Runf +}
U;I9 bK8
/* {:W$LWET
**SiteInfoBean.java SY8C4vb'h
*/ 8EEuv-aeo
package NetFox; uVU)d1N
lRdChoL$2
~_a-E
public class SiteInfoBean { F&Hrk|a
J-4:H gx
@lt#Nz
private String sSiteURL; //Site's URL ?hM64jI|
private String sFilePath; //Saved File's Path Sx\]!B@DSu
private String sFileName; //Saved File's Name Np)lIGE
private int nSplitter; //Count of Splited Downloading File L4f3X~8,b
+^<](z
c"xK`%e
public SiteInfoBean() 9{uO1O\
{//nSplitter的缺省值为5 ;=UsAB]
//default value of nSplitter is 5 S@sO;-^+
this("","","",5); A(0lM`X
} WN<zkM~3
39jG8zr=Z[
RFH0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M@ZI\
{ |WUG}G")*x
sSiteURL= sURL; ]:\dPw`A
sFilePath = sPath; ?'je)F
sFileName = sName; hpJ-r
this.nSplitter = nSpiltter; a'z7(8$$
Q5_o/wk
C8\^#5
} Y4(
;UP$yM;
snikn&
public String getSSiteURL() 7[wieYj{
{ ctJE+1#PH
return sSiteURL; 3yXY.>'
} qjc4.,/
f V(J|
IqGdfL6[(
public void setSSiteURL(String value) A+)`ZTuO
{ cFWc<55aX6
sSiteURL = value; V470C@
} ?R#)1{(8d~
\^%}M!tan
u~-8d;+?y
public String getSFilePath() !Rt>xD
{ V2G6Kw9gt
return sFilePath; ?pZOeqqu$
} &! ?eL
`~`k_7t.
IaXeRq?<
public void setSFilePath(String value) N.{D$"
{ = 9]~yt
sFilePath = value; yvYad
} K96<M);:g
r>U@3%0&
m9Hit8f@Q
public String getSFileName() C2Tyoza
{ xZv#Es%#
return sFileName; puM3g|n@
} t<viX's
}Z,x~G
!GGkdg*-*9
public void setSFileName(String value) &JI8]JmU)
{ W{gb:^;zb
sFileName = value; uRr o?m<
} ^`>/.gL
$p?aVO
J9[r|`gJ(
public int getNSplitter() d<N:[Y\4l
{ \K!VNB>h
return nSplitter; (ICd}
} xUistwq
(*)hD(C5
9p2&)kb6
public void setNSplitter(int nCount) %1$,Vs<RH
{ tC9n k5~
nSplitter = nCount; q%?in+l
} %-0t?/>
} )%@J=&G8TT
Hg$lXtn]
)TH@#1
/* #?9;uy<j.q
**Utility.java v oj^pzZ
*/ Tyf`j,=
package NetFox; >s?S+W[L
'CkIz"Wd
=>af@C.2
public class Utility { MFAH%Z$
';=O 0)u
=$Nq
public Utility() b`O'1r\Y;
{ e&aWq@D
;x@~A^<el
s6^>F/x
} W]5w \
b?QoS|<e?
//线程睡眠 _8_R 1s
public static void sleep(int nSecond) hNmJ!Uo
{ (c &mCJN
try{ FE|JHh$
Thread.sleep(nSecond); VZmLS 4E
} h|{]B,.Lh
catch(Exception e) T <ET )D7
{ o="M
e.printStackTrace (); !NvI:C_4|
} Y^EcQzLw
} 4 VW[E1<
SmSH2m-
//日志 y ~!Zg}o
public static void log(String sMsg) Q:k}Jl
{ FZslv"F
System.err.println(sMsg); <s<n
} iVq'r4S
f5VLw`m}.8
^N{h3b8
public static void log(int sMsg) R3&Iu=g
{ G^4hd i3@
System.err.println(sMsg); zL`iK"N`
} T&u5ki4NE
} Lhb35;\
"8jf81V*
41?HY{&2
/* UIN<2F_
**TestMethod.java P%&0]FCx
*/ G.abql
package NetFox; CxOob1@
Jgd'1'FOs
c>:wd@w
public class TestMethod { ARwD~Tr
a>I+]`g
ryUQU^v
public TestMethod() Z!zF\<r
{ ///xx/weblogic60b2_win.exe EF}\brD1
try{ cZU=o\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); '3DXPR^B6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;1O_M9
SiteFileFetch fileFetch = new SiteFileFetch(bean); >T3-
fileFetch.start(); MSqVlj
} /,&<6c-Q@W
catch(Exception e){e.printStackTrace ();} ,|H `e^
/quc}"__
e+BQww
} H-*yh!
zC@o
?u=Fj_N_
public static void main(String[] args) {xB!EQ"
{ as4;:
new TestMethod(); suiS&$-E
} A,hJIe
} QIvVcfM^
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