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)); |Z{ DU(?[b
} q;qY#wD@
for(int i=0;i<nEndPos.length-1;i++) JiHk`e`
{ eRwm>l"fVV
nEndPos = nStartPos[i+1]; ^Ea^t.c}_
} R)5zHCwOw
nEndPos[nEndPos.length-1] = nFileLength; h<f]hJ`ep
} U3ao:2zP
} gl"1;C
~f!iz~
R`emI7|
//启动子线程 DWar3+u&0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0%hOB:
for(int i=0;i<nStartPos.length;i++) !PY.FnZ
{ vWpkU<&3|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A/U,|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tv7A&Z)Rh
nStartPos,nEndPos,i); 75#&hi/~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j[YO1q*
fileSplitterFetch.start(); P<gr=&
} %N-f9o8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Mhj.3nN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); km#Rh^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oSqkAAGz\
nEndPos = " + nFileLength); 79Si^n1\
// fileSplitterFetch[nPos.length-1].start(); K9N\E"6ZP
XnI)s^
9"mcN3x:\e
//等待子线程结束 IgU65p
//int count = 0; xs3t~o3y
//是否结束while循环 _0]{kB.$_
boolean breakWhile = false; :f58JLX
M%Dv-D{
qHQ#^jH
while(!bStop) =^A/&[&31
{ z>./lu\
write_nPos(); +oMe\wYR$r
Utility.sleep(500); LTc=D
breakWhile = true; XDrNc!XN
4^rO K
J$Nc9?|ZZ
for(int i=0;i<nStartPos.length;i++) 1K'.QRZMb9
{ Oe*+pReSD
if(!fileSplitterFetch.bDownOver) 2OJ=Xb1
{ Epf[8La
breakWhile = false; X$4 5<oz
break; aI0}E O
} ^(8(z@y
} /iekww^54
if(breakWhile) L[FNr&
break; c|^#v8x^/
%.*?i9}
n9Xssl0
//count++; Kn<z<>vO
//if(count>4) vg/:q>o
// siteStop(); @`6db
} a\m@I_r.N
JQ.w6aE
QX j4cg
System.err.println("文件下载结束！"); w$5#jJX\
} 3d|n\!1r
catch(Exception e){e.printStackTrace ();} - &/n[EE
} MHVHEwr.{
SXx2
")87GQ(R
//获得文件长度 ;0f?-W?1
public long getFileSize() 'YcoF;&[C
{ On{p(|l
int nFileLength = -1; (X"WEp^Q{I
try{ Gf{FFIe(
URL url = new URL(siteInfoBean.getSSiteURL()); g^EkRBU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^KK6 d
httpConnection.setRequestProperty("User-Agent","NetFox"); a:(.{z?nM
s1eGItx[w
g :me:M
int responseCode=httpConnection.getResponseCode(); 5-ju5z?=
if(responseCode>=400) c_xo6+:l
{ 1$g]&'
processErrorCode(responseCode); K;wd2/jmJ
return -2; //-2 represent access is error ZzuEw
} bQ"w%!
`/mcjKQ&9y
iYJzSVO
String sHeader; do:3aP'S,
62X;gb
ag$mc8-p[
for(int i=1;;i++) 6(`Bl$M9
{ hKtc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~#b&UR
//Utility.log(in.readLine()); \*V`w@
sHeader=httpConnection.getHeaderFieldKey(i); Z+< zKn}
if(sHeader!=null) k-b0Eogp]
{ 2vit{
if(sHeader.equals("Content-Length")) PfI~`ke
{ buRK\C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y0R5YCq\":
break; 8Jd\2T7h
} tC=`J%Ik
} D:gskK+o6M
else , LP |M:
break; *$ihNX]YG
} ?{"_9g9
} il \q{Y o
catch(IOException e){e.printStackTrace ();} *k(>Qsb "
catch(Exception e){e.printStackTrace ();} >~kSe=Hsb4
dX0"h5v1
X=<-rFW
Utility.log(nFileLength); :-=,([TJ
vElVw. P
zd+_ BPT
return nFileLength; ;MqH)M
} cj:!uhZp7
Ed%8| M3
J0e~s
//保存下载信息（文件指针位置） RfMrGC^?
private void write_nPos() {:VUu?5-t;
{ l0m\2Ttf
try{ $~|#Rz%v
output = new DataOutputStream(new FileOutputStream(tmpFile)); :dtX^IT
output.writeInt(nStartPos.length); Sn\S`D
for(int i=0;i<nStartPos.length;i++) 7B`,q-x.
{ y~JCSzpU
// output.writeLong(nPos); a_UVb'z
output.writeLong(fileSplitterFetch.nStartPos); k:Iz>3O3]
output.writeLong(fileSplitterFetch.nEndPos); S0_#h)
} BTwLx-p9t
output.close(); m8q3Pp
} 7[wHNJ7)r
catch(IOException e){e.printStackTrace ();} |Go?A/'
catch(Exception e){e.printStackTrace ();} qFo'"z`84
} 5V5E,2+ 0
,haCZH{
tH_e?6]
//读取保存的下载信息（文件指针位置） X`dd"8%
private void read_nPos() |=7ouFl
{ 2l)J,z
try{ K +oFu%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S+Aq0B<
int nCount = input.readInt(); 5YlY=J
nStartPos = new long[nCount]; DlkHE8r\
nEndPos = new long[nCount]; (GVH#}uB
for(int i=0;i<nStartPos.length;i++) =|lKB;
{ NzmVQ-4
nStartPos = input.readLong(); Fg3VD(D^U
nEndPos = input.readLong(); +UxhSFU
} l:O6`2Z
input.close(); gHLBtl/
} vV.TK_y
catch(IOException e){e.printStackTrace ();} [Yx)`e
catch(Exception e){e.printStackTrace ();} fI2/v<[
} 0W|}5(C
a}Db9=
etX&o5A
private void processErrorCode(int nErrorCode) Yq;|Me{h
{ E\V-<]o
System.err.println("Error Code : " + nErrorCode); gWo`i
} x~Egax
=v4;t'_^
qW57h8M
//停止文件下载 mJ=3faM
public void siteStop() pSQ)DqW
{ <MhjvHg
bStop = true; !c`KzqP
for(int i=0;i<nStartPos.length;i++) x/NR_~Rnk
fileSplitterFetch.splitterStop(); qRg^Bp'VD#
<_HK@E<_HO
gO*:<B g
} v$R+5_@[l
} FhZ^/= As
//负责部分文件的抓取 i<N[sO
**FileSplitterFetch.java _~aFzM
*/ I$K?,
package NetFox; &TqY\l
H[ 6L!
tn-_3C
import java.io.*; m_Owe/BC#m
import java.net.*; IL?mt2IQ>
\#P>k;D
D(}w$hi8
public class FileSplitterFetch extends Thread { Y<U"}}
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~{,U%B
String sURL; //File URL |wASeZMO2
long nStartPos; //File Snippet Start Position ;P9P2&c8c
long nEndPos; //File Snippet End Position h)[{{JSf
int nThreadID; //Thread's ID =yv_i]9AN
boolean bDownOver = false; //Downing is over s? /#8 `
boolean bStop = false; //Stop identical =HT:p:S
FileAccessI fileAccessI = null; //File Access interface Ys@M1o
ecK{+Z'G
bI)ItC_wf!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LRO'o{4$E
{ Y6T1_XG
this.sURL = sURL; 9$&+0
this.nStartPos = nStart; ]UG+<V ,:
this.nEndPos = nEnd; ~7$E\w6
nThreadID = id; u<x2"0f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jseyT#2
} c+PT"/3
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VeixwGZ.
public void run() Z^i=51
{ HC0q_%j
while(nStartPos < nEndPos && !bStop) z-|gw.y
{ &6fNPD(|
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\u@4eBAV
try{ [(v?Z`cX\
URL url = new URL(sURL); %2Q:+6)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =;DmD?nZ
httpConnection.setRequestProperty("User-Agent","NetFox"); Le3H!9lbc
String sProperty = "bytes="+nStartPos+"-"; ,i>u>YNZ
httpConnection.setRequestProperty("RANGE",sProperty); 9"Vch;U$
Utility.log(sProperty); O9OD[VZk
DSGtt/n
WAPN,WuW
InputStream input = httpConnection.getInputStream(); :.kc1_veYS
//logResponseHead(httpConnection); (_G&S~@.
[+0rlmB
Va^Y3/
byte[] b = new byte[1024]; Z;kRQ
int nRead; )1Rn;(j9Re
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QC7Ceeh]4
{ xU$A/!oK
nStartPos += fileAccessI.write(b,0,nRead); Wbo{v r[2+
//if(nThreadID == 1) ySP1,xq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rU?sUm,ch
} / fBi9=}+
q{v:T}Q|A
D=}UKd
Utility.log("Thread " + nThreadID + " is over!"); q)%F#g
bDownOver = true; "Y(stRa
//nPos = fileAccessI.write (b,0,nRead); lz>YjK:
} A/n-.ci
catch(Exception e){e.printStackTrace ();} C Z8Fe$F
} ?E1<>4S8
} P" +!mSe^~
&u5OL?>
pME17 af
//打印回应的头信息 j8p</gd
public void logResponseHead(HttpURLConnection con) ,ra!O=d~0
{ Sa5+_TW
for(int i=1;;i++) -dXlGOD+C
{ ? b;_T,S[
String header=con.getHeaderFieldKey(i); (_S`9Z8=
if(header!=null) 6&~8TH
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qEvHrsw},
Utility.log(header+" : "+con.getHeaderField(header)); \lj.vzD-A
else r*#ApM"L
break; .!uXhF'
} *_G(*yAe(
} @Qw~z0PE<l
^(<Ecdz(
e~#;ux
public void splitterStop() -#0(Jm'
{ @c&}\#;
bStop = true; E6"+\-e
} .FUws
VO#x+u]/
D$C>ZF
} D^cv 8 8<
U5X\RXy~
*1FDK{
/* ^%(HZ'$wC
**FileAccess.java RTN?[`
*//文件访问(定位，写) l1(6*+
package NetFox; 0vN<0
import java.io.*; W\mj?R
N ]KS\
\Fd6Q_
public class FileAccessI implements Serializable{ <A{|=2<
!cP2,l'f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cj ?aCVa
RandomAccessFile oSavedFile; rG7E[kii
long nPos; ;pk4Voo$
p,_,o3@~
2tz%A~}4
public FileAccessI() throws IOException vW`Dy8`06
{ "B18|#v
this("",0); Leg)q7n
} y|r+<
l=EnK"aU
`SDpOqfIrP
public FileAccessI(String sName,long nPos) throws IOException q-7C7q
{ t8vR9]n
oSavedFile = new RandomAccessFile(sName,"rw"); 5%H(AaG*q
this.nPos = nPos; W5C8$Bqm
oSavedFile.seek(nPos); -Jqm0)2
} >Z0F n
~Mk{2;x
L`sg60z
public synchronized int write(byte[] b,int nStart,int nLen) 9o)sSaTx=
{ EPEy60Rx5
int n = -1; GnAG'.t-Z
try{ R/!lDv!
oSavedFile.write(b,nStart,nLen); w'Y(doY,
n = nLen; ?= G+L0t
} TcW-pY<N
catch(IOException e) 5ynBVrYf
{ uD'yzR!]+
e.printStackTrace (); i}&&rr
} y]3`U UvXD
E[Xqyp!<
'3%JhG)#
return n; IP?15l w
} [{!K'V
`'W/uCpl
QoLp$1O(y
} "|N58%
"0*yD[2
KjWF;VN*[3
/* 9Wu c1#
**SiteInfoBean.java 7Shau%2C
*/ RB\ Hl
package NetFox; [zC1LTXe
%rFR:w`{
i2+r#Hw#5R
public class SiteInfoBean { wDQ@$T^vh
!+UU[uM
8+f{ /
private String sSiteURL; //Site's URL /gX=79
private String sFilePath; //Saved File's Path [c^!;YBp)
private String sFileName; //Saved File's Name N F$k~r
private int nSplitter; //Count of Splited Downloading File *|gY7Av*
HbI'n,+
7`s* {
public SiteInfoBean() v9,<2
{//nSplitter的缺省值为5 H^Mfj!S
//default value of nSplitter is 5 5VS};&f
this("","","",5); Ie<H4G5Vh
} vU,V[1^a
&6feR#~A
bUzo>fm_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,59G6o
{ tG7F!um(
sSiteURL= sURL; [X9T$7q#
sFilePath = sPath; DX2_}|$!
sFileName = sName; SD/=e3
this.nSplitter = nSpiltter; |D% O`[k+
$#z-b@s=B
{4n
} 4,,@o
(U{,D1?
Z5j\ M
public String getSSiteURL() [S~/lm
{ $+k|\+iJ
return sSiteURL; z|F38(%JJN
} > `1K0?_
&%UZ"CcA
c$.Zg=
public void setSSiteURL(String value) N&uRL_X.
{ BS.5g<E2q
sSiteURL = value; `K7UWtp
} 4-CGe
sck.2-f"
=dT #x
public String getSFilePath() }6'%p Bd
{ _4f=\
return sFilePath; UVd ^tg
} HJi FlL3
WaPuJ5;e
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public void setSFilePath(String value) lt{Df~c
{ \wKnX]xGf
sFilePath = value; $$ 9!4
} U!GfDt
3v91yMx
.rwa=IW
public String getSFileName() o5E5s9n
{ GI<3L K\
return sFileName; aD&4C-,1
} /;5/7Bvj
~eyZH8&
!C& ^%a
public void setSFileName(String value) H %Dcp#k
{ d4m@u$^1B
sFileName = value; N;HG@B!m
} \>\_OfY1W
Pil_zQ4
!DM GAt\
public int getNSplitter() [ KDNKK
{ Z?<&@YQS
return nSplitter; uhm3}mWv
} h:AB`E1
3s0I<cL
|})v, oB
public void setNSplitter(int nCount) V"|`Z}XW
{ @iU(4eX
nSplitter = nCount; b&*)C#7/T
} ;d.gVR_V
} V2SHF
Q-?6o
c :2w(BVi
/* ":_~(?1+
**Utility.java )zydD=,bu
*/ \>tx:;D3
package NetFox; C)mR~Ey
o3X0c6uU
d3]<'B:nb
public class Utility { >rYkVlv
P9o=G=i
>x1yFwX}-f
public Utility() 7fC:'1]G
{ 1=_Qj}!1
[;Jq=G8&t
z?t75#u9.
} goOw.~dZ'
-cWGF
//线程睡眠 !A:d9 k
public static void sleep(int nSecond) d f j;e%H
{ ]m :Y|,:6
try{ n= q7*<l
Thread.sleep(nSecond); @e-2]z
} #]h&GX
catch(Exception e) iHT=ROL
{ q $=[v
e.printStackTrace (); j6E|j>@u
} ^x2@KMKXZ
} MJA;P7g
XE8%t=V!c$
//日志 y7Nd3\v [\
public static void log(String sMsg) P7epBWqDP
{ L1kAAR
System.err.println(sMsg); T7^?j :kJ/
} C;%1XFzM
T930tX6"h
%us#p|Ya
public static void log(int sMsg) Js&.p9S2
{ `<6FCn4{X
System.err.println(sMsg); VsDY,=Ww
} 0$_WIk
} h!7Lvh`o
hGcu(kAC,
92ngSaNC
/* BZ,{gy7g7X
**TestMethod.java Y[s}?Xu]w#
*/ s`|KT&r
package NetFox; G1Vn[[%k
p~v0pi
P9x':I$
public class TestMethod { D,()e^o
{mB!mbr
}S;A%gYm
public TestMethod() w3&L 6|,
{ ///xx/weblogic60b2_win.exe A@eR~Kp ^
try{ 30O7u3Zrb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *6G@8TIh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <b?$-Rx
SiteFileFetch fileFetch = new SiteFileFetch(bean); x->+wJm@s
fileFetch.start(); }tQ^ch;Q
} _:%i6c*"
catch(Exception e){e.printStackTrace ();} ]!uId#OH
TPYh<p#
?KWo1
} @p@b6iLpO
$$XeCPs0
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public static void main(String[] args) 72vp6/;)
{ )SJ"IY\P
new TestMethod(); z0UtKE^b
} +~sqv?8
} dU2:H}
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