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)); Bo:epus}\
} -w+.'
for(int i=0;i<nEndPos.length-1;i++) J>X@g;
{ 0LW3VfvToN
nEndPos = nStartPos[i+1]; u?>},M/
} 8jCho
nEndPos[nEndPos.length-1] = nFileLength; 9DBX.|
} ij:xr% FJ
} 'e:4
]MCH]/
U<Oc&S{]*
//启动子线程 Vg62HZ |
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zd_N' :6
for(int i=0;i<nStartPos.length;i++) Ry[7PLn]
{ p;4FZ$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |X{j^JP5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), C.4(8~Y=~
nStartPos,nEndPos,i); 6$#,$aO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `n,RC2yo
fileSplitterFetch.start(); h.-L_!1B7
} G5hRx@vfrL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `K VSYC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 39^+;Mev
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )EMlGM'2q
nEndPos = " + nFileLength); 5CnNp?.t^
// fileSplitterFetch[nPos.length-1].start(); `U0XvWPr[
/'oo;e
9ad`q+kY
//等待子线程结束 xkf2;
//int count = 0; N-N]BS6
//是否结束while循环 YUSrZ9Yg
boolean breakWhile = false; <=CABWO.
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_"*vj-{-y
while(!bStop) |i B#
{ 8Z}%,G*n
write_nPos(); 3]S_w[Q4
Utility.sleep(500); / 8O=3
breakWhile = true; )h ,v(Rxa
OGEe8Z9Jt
<uU<qO;6
for(int i=0;i<nStartPos.length;i++) @nqM#
{ [<r.M<3
if(!fileSplitterFetch.bDownOver) b4:{PD~Mh
{ K1YxF
breakWhile = false; jNbVp{%/S}
break; h5P ]`r
} vo Et\H
} yIiVhI?X
if(breakWhile) = 1veO0
break; iB99.,o-&
(e_<~+E
=~s+<9c]
//count++; _an0G?7
//if(count>4) q4X(_t
// siteStop(); BN&)5M?Xt6
} nh7_ jEX
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_zbIS&4
System.err.println("文件下载结束！"); ,J2qLH1
} NPv.7,
catch(Exception e){e.printStackTrace ();} ~(*tcs]hY
} x+~!M:fAc9
P,zQl;
/7#MJH5b6
//获得文件长度 :}36;n<['
public long getFileSize() {1=|H$wKg
{ %4` U' j
int nFileLength = -1; O\uIIuy
try{ {tYY _BI<
URL url = new URL(siteInfoBean.getSSiteURL()); $S>bcsAy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )cL(()N
httpConnection.setRequestProperty("User-Agent","NetFox"); C@;e<
qu#xc0?
m*1
int responseCode=httpConnection.getResponseCode(); {a\! 1~
if(responseCode>=400) ,ye[TQ\,M
{ VJ h]j(
processErrorCode(responseCode); m|B)A"Sm
return -2; //-2 represent access is error }>y!I5O
} YeT{<9p
K%`]HW@I{
C ]B P}MY<
String sHeader; qh W]Wd"g
\{Q_\s&)
yQ^,>eh
for(int i=1;;i++) QiA}0q3]0
{ D HQxu4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #Rfcp!
//Utility.log(in.readLine()); #|+4`Gf^
sHeader=httpConnection.getHeaderFieldKey(i); IlO,Ql
if(sHeader!=null) 6jm?d"9
{ 2aR9vmR
if(sHeader.equals("Content-Length")) 3S#p4{3
{ A|K=>7n]U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h$sOJs~6h
break; GwXhn2
} s%rmfIp"
} MrUjqv6a[
else =!DX,S7
break; [So1`IA6
} n>,GmCo
} m<#^c?u
catch(IOException e){e.printStackTrace ();} _'G'>X>}WU
catch(Exception e){e.printStackTrace ();} G3y8M|:
]7TOA$Q
UsA fZg8
Utility.log(nFileLength); E,ilJl\
5|jY
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return nFileLength; ]Hl{(v\HO
} :B=Gb8?
^B%ki
'y>Y*/
//保存下载信息（文件指针位置） qGhg?u"n:
private void write_nPos() WqM| nX
{ i/C% 1<
try{ cGm?F,/`
output = new DataOutputStream(new FileOutputStream(tmpFile)); [;yH.wn#5
output.writeInt(nStartPos.length); V=fh;p
for(int i=0;i<nStartPos.length;i++) `<~=6H
{ 9fs-|E[5
// output.writeLong(nPos); Vp1ct06^
output.writeLong(fileSplitterFetch.nStartPos); a6xo U;T
output.writeLong(fileSplitterFetch.nEndPos); +-),E.
} Odw'Ua
output.close(); Wj!+ E{y<r
} *pD|N
catch(IOException e){e.printStackTrace ();} $8(QBZq
catch(Exception e){e.printStackTrace ();} a_0I)' ?
} )l! /7WKY
u^MRKLn
0#=xUk#LP`
//读取保存的下载信息（文件指针位置） dg~lz80
private void read_nPos() WC=d@d)M
{ Vh;|qF 9
try{ vm;%713#1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n8)&1 q?V
int nCount = input.readInt(); yEjiMtQll]
nStartPos = new long[nCount]; \p.yR.
nEndPos = new long[nCount]; >l%8d'=Jl
for(int i=0;i<nStartPos.length;i++) w-R.)
{ zjow %
nStartPos = input.readLong(); ->?tB1}^
nEndPos = input.readLong(); j[R.UB3J
} S[7^#O.)
input.close(); tw.GBR
} *aS+XnT/
catch(IOException e){e.printStackTrace ();} jTg~]PQ^
catch(Exception e){e.printStackTrace ();} |,=^P`#%
} ~Gh7i>n*
1,h:|
djnES,^%9
private void processErrorCode(int nErrorCode) MCEHv}W
{ 7T6Zlp
System.err.println("Error Code : " + nErrorCode); 5y g`TW
} $v#`2S(7
aaKf4}
7q;`~tbC
//停止文件下载 A/:_uqm4
public void siteStop() EAXl.Y. $
{ ZCZ@ZN
bStop = true; ^Lc\{,m
for(int i=0;i<nStartPos.length;i++) i\^4EQ
fileSplitterFetch.splitterStop(); >W >Ei(f
ORF:~5[YS`
+XO\#$o>W
} -n[(0n3c
} [[^95:
//负责部分文件的抓取 :] U\{;q2
**FileSplitterFetch.java 45wtl/^9
*/ +a N8l1
package NetFox; ;ltk}hJ]
8kdJtEW3
T\$i=,_$
import java.io.*; -8FUR~WJ
import java.net.*; Nb9GrYIS
Bf#cBI
R3a}YwJFXF
public class FileSplitterFetch extends Thread { -@_v@]:
Q 318a0
eBxm
String sURL; //File URL 1|"BpX~D
long nStartPos; //File Snippet Start Position x$o^;2Z
long nEndPos; //File Snippet End Position x>##qYT
int nThreadID; //Thread's ID _ {wP:dI "
boolean bDownOver = false; //Downing is over )kI**mI}
boolean bStop = false; //Stop identical 3TCRCz
FileAccessI fileAccessI = null; //File Access interface Ic_NQ<8
>l AtfN='
WG6 0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2YKa <?_
{ &qdhxc4
this.sURL = sURL; IKPGqoM
this.nStartPos = nStart; S:}"gwFM
this.nEndPos = nEnd; mgVYKZWL-i
nThreadID = id; $57b.+2n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yj_>G
} 6*>Lud
TbNH{w|p
MaHP):~
public void run() MomHSvQ\
{ 7pY :.iVO
while(nStartPos < nEndPos && !bStop) `ROHB@-
{ 6uo;4}0
Kd^.>T-
yCN_vrH>
try{ [H<TcT8
URL url = new URL(sURL); /QyKXg6)l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G'G8`1Nj
httpConnection.setRequestProperty("User-Agent","NetFox"); HW~-GcU-o
String sProperty = "bytes="+nStartPos+"-"; r#4/~a5i~
httpConnection.setRequestProperty("RANGE",sProperty); UWKgf? _
Utility.log(sProperty); 7>j~;p{
5a_8`csu
CKK}Z;~:
InputStream input = httpConnection.getInputStream(); ]r|oNGD)G
//logResponseHead(httpConnection); RM `qC
$+7uB-KsU
'-RacNY
byte[] b = new byte[1024]; W!? h2[
int nRead; Qw'905;(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \*e\MOp6
{ BXYH&2]Q
nStartPos += fileAccessI.write(b,0,nRead); S=mqxIo@m
//if(nThreadID == 1) m!%aB{e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); thJ~* 0^
} _;;Zz&c
%;dj6):@
(XVBH1p"
Utility.log("Thread " + nThreadID + " is over!"); oXnaL)Rk
bDownOver = true; eyyME c!
//nPos = fileAccessI.write (b,0,nRead); '{jr9Vh
} f2;.He
catch(Exception e){e.printStackTrace ();} _i+@HXR &
} 8;DDCop 8L
} MHK|\Z&e7
y')OmR2h
/v+)#[]>
//打印回应的头信息 6j<!W+~G
public void logResponseHead(HttpURLConnection con) qtZ? kJ
{ PT6]qS'1
for(int i=1;;i++) {k)gDJU
{ \\FT.e6
String header=con.getHeaderFieldKey(i); .N qXdari
if(header!=null) jhm??Af
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m<-ShRr*b
Utility.log(header+" : "+con.getHeaderField(header)); I} jgz
else 3@gsKtA&H4
break; Ck Nl;g l
} }<0N)dpT
} Xv-p7$?f
m|qktLx
1Hr}n6s
public void splitterStop() 22CET9iCe
{ kJ_8|
bStop = true; |]*3En:
} k9;^|Cm k
c;$4}U4
ai/|qYf
} _?I{>:!|
cl%+m
V]p{jLG
/* Mu?|<#s
**FileAccess.java hL&$` Q
*//文件访问(定位，写) {6zNCO
package NetFox; g F*AS(9
import java.io.*; /D&&7;jJ
hF,|()E[
4KM-$h,4O
public class FileAccessI implements Serializable{ +P2oQ_Fk`9
Cd}^&z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \_ 3>v5k|
RandomAccessFile oSavedFile; IW0S*mO$
long nPos; i7Up AHd/
DW. w=L|5R
RSp wU;o6z
public FileAccessI() throws IOException .$18%jH#
{ $8=|<vt
this("",0); } a9Ah:.7/
} R c+olJ^5
&<PIm
P]43FPb
public FileAccessI(String sName,long nPos) throws IOException V\;Xa0
{ _B0(1(M<2
oSavedFile = new RandomAccessFile(sName,"rw"); \wK&wRn)
this.nPos = nPos; f"ndLX:'}
oSavedFile.seek(nPos); q!ZM Wg
} {]T?)!Vm
@Vre)OrN#
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public synchronized int write(byte[] b,int nStart,int nLen) Ek_5% n
{ hIJtu;}zU
int n = -1; }5;4'l8
try{ >rCD5#DG
oSavedFile.write(b,nStart,nLen); {o}U"b<+Ra
n = nLen; )L:zr#
} [IL*}M!
catch(IOException e) "b} mVrFh
{ dHc\M|HCC
e.printStackTrace (); ~3F'X
} uuC ["Z
Jka>Er
{zwH3)|Hn
return n; ngo> ^9/8
} -&1(~7
nkW})LyB\
vI{aF- #
} (pxH<k=Ah
.kT]^rv ;
yLnQ9BXB&
/* XX8HSw!w
**SiteInfoBean.java 3uLG$`N
*/ q+?<cjVg
package NetFox; VdlT+'HF
DB/~Z
mmTpF]t ?`
public class SiteInfoBean { 7Sx|n}a-3
z'YWomfZm
:@(('X(".
private String sSiteURL; //Site's URL gP2zDI
private String sFilePath; //Saved File's Path tT}b_r7h(1
private String sFileName; //Saved File's Name jn<?,UABD
private int nSplitter; //Count of Splited Downloading File uX_H;,n
w% %q/![uy
~g{j)"1
public SiteInfoBean() *~vB6V|1
{//nSplitter的缺省值为5 Er;/zxg9p
//default value of nSplitter is 5 l0qaTpn
this("","","",5); 1Bj.MQ^
} |oY{TQ<<d
$1yO Zp5
lsz3'!%Y)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Rx-\B$G
{ fN&,.UB^p
sSiteURL= sURL; e^y9Kmd
sFilePath = sPath; m2PUU/8B/
sFileName = sName; uo#1^`P
this.nSplitter = nSpiltter; J(7#yg%5
aAg Qv*
m'rDoly"62
} p='j/=
J @Hg7Faz
|[SHpcq>
public String getSSiteURL() s L^+$Mq6
{ d?zSwLsl
return sSiteURL; 1}(22Q;
} TeHJj`rdAU
O~3 A>j
u{sHuVl
public void setSSiteURL(String value) pY31qhoZ.
{ dGUP|O
sSiteURL = value; 0AQazhm
} 6G8No-#y
z`{sD]
`3;EJDEdbi
public String getSFilePath() l6 G6H$
{ LA3m,
return sFilePath; UB$}`39@
} j-<-!jTd
O_FB^BB
Nk'<*;e
public void setSFilePath(String value) 4MgN
{ OX_y"]utU
sFilePath = value; +_5*4>MC
} LV:L0D7y
R(1:I@<?E
hA7=:LG
public String getSFileName() sscbf
{ 5YY5t^T
return sFileName; :""HyjY!
} 'RjEdLrI
Lq(=0U\"P
_.5{vGyxr
public void setSFileName(String value) 'OY4Q'Z
{ &Hoc`u
sFileName = value; >h7(kj:
} yE:y[k0E
yXNr[7
Q]WBH_j
public int getNSplitter() c8uaZvfW
{ \c_g9Iqa
return nSplitter; ;s+/'(*
} OSBR2Z;=
F9%_@n
K~L&Z?~|E
public void setNSplitter(int nCount) m?e/MQr
{ "N+4TfXy
nSplitter = nCount; s)-An(Uw
} { DYY9MG8
} S?688
5CI{&E
h FU8iB`Q
/* }-3 VK%
**Utility.java X=QX9Ux?^
*/ #Vk?
package NetFox; "laf:Ty1
6n9/`D!
kV'zAF v
public class Utility { *zdD4I=
4C;;V m4~
Fb,*;M1'
public Utility() #}7T$Va
{ HPtMp#`T
W@R7CQE@
Rw+r1vW:A
} )tlj{ 7p
iv*RE9?^
//线程睡眠 pwo$qs(p
public static void sleep(int nSecond) "6U0 !.ro@
{ g QBS#NY
try{ T+Yv5l
Thread.sleep(nSecond); x^lcT
} )1At/mr
catch(Exception e) a6Vfd&
{ a*p|Ij
e.printStackTrace (); 13?:a[~=Y
} *7AB0y0k
} Ii0\Skb
B^2r4 9vC
//日志 j2G^sj"|
public static void log(String sMsg) ]]|#+$ ~
{ SdnnXEB7
System.err.println(sMsg); )Jt. Z^J<
} mm>l:M TF
GCl *x:
Q>5f@aN
public static void log(int sMsg) AXbb-GK
{ tddwnpnSw
System.err.println(sMsg); Z_GGH2u
} ct\msG }b:
} T@1;Nbz]
e66Ag}Sw|
.$\-{)
/* 2J=`"6c
**TestMethod.java =%` s-[5b
*/ xP\s^]e
package NetFox; #$UwJB]_D
onuG
d/ Lz"
public class TestMethod { 5(<O?#P
{IOc'W-C#2
-nGcm"'6F
public TestMethod() =-^A;AO(
{ ///xx/weblogic60b2_win.exe x-i,v"8
try{ 0MRWx%CR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !/G}vu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @lB{!j&q
SiteFileFetch fileFetch = new SiteFileFetch(bean); A;8kC}
fileFetch.start(); jU-LT8y:
} 3I 0pHP5
catch(Exception e){e.printStackTrace ();} q 4Pv\YO
/ =9Y(v
X3sAy(q
} (Z<@dkO?)
<lzC|>BG
OV{v6,>O
public static void main(String[] args) :2j`NyLI.
{ RQ=rB9~:ZN
new TestMethod(); U*+-#
} 18X?CoM~
} h1S)B|~8
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