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)); }s2CND
} :(q4y-o6
for(int i=0;i<nEndPos.length-1;i++) W6?=9].gc
{ J.iz%8
nEndPos = nStartPos[i+1]; N XB8u6
} Uw4iWcC
nEndPos[nEndPos.length-1] = nFileLength; BA a:!p
} =eA|gt
} yzEyOz@Q
EW$drY@
Uz;^R@
//启动子线程 SFg4}*"C/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; imOIO[<;
for(int i=0;i<nStartPos.length;i++) L,zx\cj?z
{ or-k~1D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a"s2N%{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 091m$~r*
nStartPos,nEndPos,i); 60{G 4b)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oyVT
fileSplitterFetch.start(); jTwSyW
} bB@=J~l4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), P$'PB*5d|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TTG=7x:3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CC^D4]ug
nEndPos = " + nFileLength); _JC*4
// fileSplitterFetch[nPos.length-1].start(); s(_z1
7sVM[lr<
O+!4KNN.-
//等待子线程结束 sm##owI
//int count = 0; Rd8mn'A
//是否结束while循环 %LnLB
boolean breakWhile = false; hw"2'{"II
/5 z+N(RFC
bfeTf66c
while(!bStop) ,u@:(G
{ Lginps[la
write_nPos(); .*NPoW4Kv
Utility.sleep(500); tDETRjTA
breakWhile = true; &pK0>2
:%sG'_d
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for(int i=0;i<nStartPos.length;i++) @+;.W>^h
{ .i\FK@2
if(!fileSplitterFetch.bDownOver) ;)ay uS sQ
{ )pI( <
breakWhile = false; G=qlE?j`j
break; / 0$!.
} '&Ur(axs
} 5CnNp?.t^
if(breakWhile) d/GSG%zB
break; tnpEfi-
m 70r'b]
Z6B$\Q5Od
//count++; gZHgL7@
//if(count>4) $\/i t
// siteStop(); AXcmN
} pI f6RwH}%
P^o@x,V!&
U/FysN_N!
System.err.println("文件下载结束！"); [vI ;A!
} / 8O=3
catch(Exception e){e.printStackTrace ();} )h ,v(Rxa
} OGEe8Z9Jt
m +A4aQ9
)E9c6'd
//获得文件长度 O<fy^[r:`
public long getFileSize() ~F@p}u8TV
{ bD)"Jy
int nFileLength = -1; )fo0YpE^|
try{ HH6n3c!:mm
URL url = new URL(siteInfoBean.getSSiteURL()); cZ%tJ(&\7X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R|@~<*
httpConnection.setRequestProperty("User-Agent","NetFox"); idHI)6!
a /]FlT
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int responseCode=httpConnection.getResponseCode(); UDZ0ne0-
if(responseCode>=400) 0fj C>AS
{ o w(9dB&E
processErrorCode(responseCode); @|h9jx|
return -2; //-2 represent access is error RKrNmD*rk*
} 1N65 M=)
~%lUzabMa
fAkfNH6
String sHeader; %1 RWF6
[PXq<ST
|WUM=g7PC
for(int i=1;;i++) OL_#Uu
{ B0 A`@9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7"Nda3
//Utility.log(in.readLine()); ^EN )}:%Z
sHeader=httpConnection.getHeaderFieldKey(i); 0"j:-1
if(sHeader!=null) z3[J sE%
{ tvno3"
if(sHeader.equals("Content-Length")) 3AENY@*
{ /\Cf*cJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;k0Jl0[}
break; .dYv.[?hL
} zT}vaU6
} h#Rza-?"\
else ;d>n2
break; G8'{nPA~
} t<c7%i#Od
} IkmEctAU
catch(IOException e){e.printStackTrace ();} k|>yFc
catch(Exception e){e.printStackTrace ();} q'trd};xR
M_+W5Gz<
8wO4;
Utility.log(nFileLength); a/s5Oit2'X
&kvmLOI
$XcH.z
return nFileLength; AJ}m2EH
} LV1drc
iM7^
UM0Ws|qx&
//保存下载信息（文件指针位置） 0N)DHD?U
private void write_nPos() vC1fKo\p
{ L9^M?.a
try{ *BrGh
output = new DataOutputStream(new FileOutputStream(tmpFile)); izcjI.3e,
output.writeInt(nStartPos.length); GwXhn2
for(int i=0;i<nStartPos.length;i++) "]2^O
{ JXRU9`3)A
// output.writeLong(nPos); =!DX,S7
output.writeLong(fileSplitterFetch.nStartPos); [So1`IA6
output.writeLong(fileSplitterFetch.nEndPos); n>,GmCo
} Yx,E5}-
output.close(); _'G'>X>}WU
} =mX26l`B
catch(IOException e){e.printStackTrace ();} o=!_.lDF:
catch(Exception e){e.printStackTrace ();} %hmRh~/&
} &=S:I!9;;
J9t?;3
1D)0\#><
//读取保存的下载信息（文件指针位置） H;<>uELie
private void read_nPos() `zq+Xl
{ z{ M2tLNb
try{ ' A+L #
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'aV'Am+:
int nCount = input.readInt(); -B/'ArOo]
nStartPos = new long[nCount]; S W6oaa81
nEndPos = new long[nCount]; K0oF=|
for(int i=0;i<nStartPos.length;i++) V=&M\58
{ _U LzA
nStartPos = input.readLong(); [f {qb\
nEndPos = input.readLong(); X}]A_G
} x'?p?u~[
input.close(); SAitufS
} 7l/ZRz}1
catch(IOException e){e.printStackTrace ();} p<\!{5:
catch(Exception e){e.printStackTrace ();} >}+R+''nR
} :81d~f7
a {x3FQ
?zC{T*a
private void processErrorCode(int nErrorCode) ,)dlL tUm
{ /zXOtaG
System.err.println("Error Code : " + nErrorCode); IIT[^_g
} 6`6 / 2C$%
%rhZH^2
iF +@aA
//停止文件下载 }=\?]9`
public void siteStop() J,?F+Qji&=
{ U8NX%*oW
bStop = true; LauGT* z!
for(int i=0;i<nStartPos.length;i++) 1MO-60
fileSplitterFetch.splitterStop(); ->?tB1}^
w oIZFus
?%~^PHgZ|
} L#'XN H"
} v,*C>u\3s
//负责部分文件的抓取 g5pFr=NV
**FileSplitterFetch.java :JX2GRL4
*/ 5_](N$$
package NetFox; d^M*%az
1anh@T.
479X5Cl
import java.io.*; N2HD=[*cr
import java.net.*; __7}4mA
PCL ;Z
9,JM$ Y {
public class FileSplitterFetch extends Thread { &L+.5i
G!B:>P|\l
m44a HBwId
String sURL; //File URL EAXl.Y. $
long nStartPos; //File Snippet Start Position ZCZ@ZN
long nEndPos; //File Snippet End Position ^Lc\{,m
int nThreadID; //Thread's ID i\^4EQ
boolean bDownOver = false; //Downing is over >W >Ei(f
boolean bStop = false; //Stop identical 5rbb ,*
FileAccessI fileAccessI = null; //File Access interface +ansN~3
=+mb@#="m
} )Lz%Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7$g$p&,VX
{ w1-P6cf
this.sURL = sURL; /i27F2NQm
this.nStartPos = nStart; Nc4;2~XwRp
this.nEndPos = nEnd; J]Z~.f="
nThreadID = id; &)+H''JY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <},JWV3
} [mjie1j/<
#|,cy,v4
|LbAW/9a
public void run() vC@^B)5gb
{ *{+{h;p
while(nStartPos < nEndPos && !bStop) #O;JV}y
{ E X'PRNB,
a9p:k ]{
! #! MTk
try{ ILAn2W
URL url = new URL(sURL); 2IM31 .
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YI7M%B9Lj
httpConnection.setRequestProperty("User-Agent","NetFox"); U'9z.2"}9
String sProperty = "bytes="+nStartPos+"-"; q!'p
httpConnection.setRequestProperty("RANGE",sProperty); _h#I}uJ~
Utility.log(sProperty); <,GVrVH=t"
3Ji$igL
A&Aj!#
InputStream input = httpConnection.getInputStream(); 0mUVa=)D
//logResponseHead(httpConnection); &*7KQd
9NU0K2S
p$|7T31 *
byte[] b = new byte[1024]; eZU9L/w:
int nRead; @j}%{Km]Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) m#8PX$_
{ ;9h;oB@
nStartPos += fileAccessI.write(b,0,nRead); %EVgSF!r
//if(nThreadID == 1) hPNMp@Nm6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #I453
} w5%i
Mhti
300w\9fn&
Utility.log("Thread " + nThreadID + " is over!"); VSDua.
bDownOver = true; 2 HQ3G~U
//nPos = fileAccessI.write (b,0,nRead); 0stc$~~v
} HrsG^x
catch(Exception e){e.printStackTrace ();} #L+:MA7H
} h,m 90Hd+
} b\`S[
`a MU2
9>9EZ?4m
//打印回应的头信息 Z#H<+S(
public void logResponseHead(HttpURLConnection con) y-bUVw!Y
{ ?hkOL$v<9}
for(int i=1;;i++) n8F5z|/
{ @ G)yz!H
String header=con.getHeaderFieldKey(i); ;H~<.QW
if(header!=null) NvJ5[W
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~o%igJ }.C
Utility.log(header+" : "+con.getHeaderField(header)); xH*X5?
else HVHv,:bPo
break; qJdlZW<
} +K'Hr:(
} ZzupK^5Z
ySmbX
.nrllVG%`
public void splitterStop() v}Ju2}IK
{ 18Y#=uH}
bStop = true; @0@ZlHwM
} sg^|dS{3D
w(6n
<8^x Mjc
} ?![[la+f
0Z8"f_GK
E(PBV
/* W/ Q*NB
**FileAccess.java byM-$l
*//文件访问(定位，写) 6qH0]7maI
package NetFox; g5@g_~ g
import java.io.*; GcdJf/k
_5-h\RB)
@GFB{ ;=
public class FileAccessI implements Serializable{ Y"MHs0O5>
l,4O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~x9]?T
RandomAccessFile oSavedFile; zd=O;T;.
long nPos; @;bBc
]oB~8d
]h,rgO;
public FileAccessI() throws IOException L\PmT
{ clB K
this("",0); Q- |Y
} s;Gd`-S>d
">oySo.B?
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public FileAccessI(String sName,long nPos) throws IOException 8#7qHT;cx
{ + t5SrO!`
oSavedFile = new RandomAccessFile(sName,"rw"); Tf86CH=)5
this.nPos = nPos; _VKI@
oSavedFile.seek(nPos); *i]?J
} Mu?|<#s
hL&$` Q
5 aA* ~\
public synchronized int write(byte[] b,int nStart,int nLen) /D&&7;jJ
{ Kp`{-dUf
int n = -1; 5.9<g>C
try{ XVN`J]XHk
oSavedFile.write(b,nStart,nLen); U-I,Q+[C[^
n = nLen; ?Afe}
} "0An'7'm
catch(IOException e) __g k:a>oQ
{ -r={P_E6
e.printStackTrace (); X/,)KTo7
} }4A] x`3
>[fu&r1
ef7{D P
return n; x=oV!x
} gJ \6cZD
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N,Eap KG
} mn/)_1',
.5(YL8d
K& #il
/* t*gZcw5 r
**SiteInfoBean.java .S/5kLul
*/ !bE-&c
package NetFox; 6Wu*zY_+
e73=*~kfR
^m|@pp
public class SiteInfoBean { l-+=Yk!X
zt(lV
6:ettdj
private String sSiteURL; //Site's URL _=GjJ~2n
private String sFilePath; //Saved File's Path $4nAb^/
private String sFileName; //Saved File's Name : {p'U2
private int nSplitter; //Count of Splited Downloading File KewW8H~tb
X4 Arn,
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public SiteInfoBean() ~L)~p%rbi
{//nSplitter的缺省值为5 fMUcVTFe
//default value of nSplitter is 5 =-h^j
this("","","",5); heVkCM :
} "v8p<JfB`
zjpZ] $
:ky`)F`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) wjA wJOw|
{ >JyS@j}
sSiteURL= sURL; H7zN|NdNw
sFilePath = sPath; 'hpOpIsHa
sFileName = sName; +%JBr+1#\
this.nSplitter = nSpiltter; 5=pE*ETJ
Q^(CqQo!<
P.Z:`P)
} \}Jznzx;
!dLu($P
2J7|y\N,
public String getSSiteURL() U#jz5<r
{ @/z\p7e
return sSiteURL; M@Th^yF+8H
} v(1 [n]y
o(*\MTt?
[,o:nry'a
public void setSSiteURL(String value) ,Z q:na
{ l0qaTpn
sSiteURL = value; 1Bj.MQ^
} /8x';hQ
$1yO Zp5
lsz3'!%Y)
public String getSFilePath() Rx-\B$G
{ fN&,.UB^p
return sFilePath; Bs"D<r&ro
} m2PUU/8B/
uo#1^`P
J(7#yg%5
public void setSFilePath(String value) !oWB5x~:P
{ m'rDoly"62
sFilePath = value; p='j/=
} $}9jv3>)
|[SHpcq>
s L^+$Mq6
public String getSFileName() ]o6ZZK
{ vqm|D&HU
return sFileName; 1}(22Q;
} TeHJj`rdAU
O~3 A>j
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public void setSFileName(String value) i2=- su
{ W/Dd7G#IC
sFileName = value; L@N%S Sf
} D=e*rrL7a
4V@%Y,:ee
Rb6BY-/J
public int getNSplitter() Pb5yz-?
{ 9\Ii$Mp
return nSplitter; LA3m,
} F>fCp
w!F>fcm
O_FB^BB
public void setNSplitter(int nCount) Nk'<*;e
{ 4MgN
nSplitter = nCount; 5vx 4F f
} +_5*4>MC
} LV:L0D7y
R(1:I@<?E
hA7=:LG
/* ;ku>_sG-
**Utility.java 5YY5t^T
*/ :""HyjY!
package NetFox; 'RjEdLrI
Lq(=0U\"P
_.5{vGyxr
public class Utility { 'OY4Q'Z
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public Utility() 67j kU!
{ j~q 7v `":
y=Y k$:-y
Zxebv#4
} :?M_U;;z2+
DQG%`-J
//线程睡眠 GcV/_Y
public static void sleep(int nSecond) btW#ebm
{ x3+ -wv
try{ =o#Z?Bn5
Thread.sleep(nSecond); \s=r[0tj!
} &jDN6n3z
catch(Exception e) A8% e_XA
{ lc,k-}n
e.printStackTrace (); m?e/MQr
} ~74Sq'j9Wt
} x@NfN*?/+i
,GSiSn
//日志 +( LH!\{^
public static void log(String sMsg) #-L0.z(
{ &~:EmLgv
System.err.println(sMsg); de:@/-|
} +7.|1x;C
KuR]X``2
Y@FYo>0O
public static void log(int sMsg) l2F#^=tp
{ E !kN h
System.err.println(sMsg); /YJo"\7
} 01.q9AGy
} GfONm6A
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,DFN:uf=l
/* P(aBJ*((~
**TestMethod.java UC`h o%OBF
*/ KL$.E!d
package NetFox; >|3Y+X
?!RbS#QV}
f^pBXz9&=
public class TestMethod { '\bokwsP
mERkC,$
Cy-p1s
public TestMethod() ZF>:m>
{ ///xx/weblogic60b2_win.exe -d,D!
try{ a*p|Ij
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Oo|JIr7i
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b7.7@Ly y
SiteFileFetch fileFetch = new SiteFileFetch(bean); o/-RGLzAo
fileFetch.start(); 8m0*89HEu
} 5{=+S]
catch(Exception e){e.printStackTrace ();} /\1'.GR
=M1}HF,7>l
Xt$qjtVM
} 6wp1jN
?mNB:-Q
3zsp6kV
public static void main(String[] args) JD*HG]
{ N@thewt|
new TestMethod(); Kbu>U{'
} <X*oW".
} & AK\Pw)
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