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)); U&i#cF
} AJ+\Qs(0
for(int i=0;i<nEndPos.length-1;i++) C$p012D1
{ +e^CL#Gs
nEndPos = nStartPos[i+1]; $K.DLqDt
} + -uQ] ^n
nEndPos[nEndPos.length-1] = nFileLength; f&j\gYWq
} B(WmJ6e
} up{0ehr
3[j,d]\|
jzJQ/ZFS
//启动子线程 svx7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XV/7K"
for(int i=0;i<nStartPos.length;i++) v%$l(
{ p>,D F9W`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &?@[bD'T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -:95ypi
nStartPos,nEndPos,i); ,4S[<(T"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vf zC2
fileSplitterFetch.start(); =igTY1|af
} Zb=;\l*&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F!3p )?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cRH(@b Xr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @<3E`j'p
nEndPos = " + nFileLength); Mq#m;v$E
// fileSplitterFetch[nPos.length-1].start(); '<3h8\"
1.M<u)1GU
}W@refS
//等待子线程结束 >yr;Y4y7K
//int count = 0; 9% C]s
//是否结束while循环 )H@<A93
boolean breakWhile = false; 'Kk/ J+6U
TFG? EO
CuK>1_Dq
while(!bStop) 1$1>cuu
{ kQe<a1 8
write_nPos(); c&1_lI,tH
Utility.sleep(500); z Ohv>a
breakWhile = true; Dt<MEpbur
[) 0JI6
KAXjvZN1
for(int i=0;i<nStartPos.length;i++) )sW!s3>S>
{ V,=5}qozQ
if(!fileSplitterFetch.bDownOver) GZWqPM4S\
{ p6NPWaBR
breakWhile = false; !@])Ut@tN
break; 1X2|jj
} x]yIe&*('
} qE3Ud:j
if(breakWhile) .?rs5[th*
break; :!l.ze{F
1) K<x
qLN\>Z,3;
//count++; jJw
//if(count>4) Iila|,cM
// siteStop(); eI:x4K,#
} Zyr|J!VF
Q|P M6ta
xv Xci W
System.err.println("文件下载结束！"); @I|kY5'c
} (1q(6!
catch(Exception e){e.printStackTrace ();} 0LXu!iix
} 5x|$q kI
E.;Hm;
n$NM
//获得文件长度 g33Y$Xdk
public long getFileSize() J/D~]U
{ Du +_dr^4
int nFileLength = -1; +zbCYA
try{ ?$ov9U_
URL url = new URL(siteInfoBean.getSSiteURL()); -(e=S^36
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %QrOEs
httpConnection.setRequestProperty("User-Agent","NetFox"); v FQ]>nX
M:(.aEe
yPT o,,ca=
int responseCode=httpConnection.getResponseCode(); gx^_bHh
if(responseCode>=400) F'>yBDm*OM
{ =w;-4
processErrorCode(responseCode); #g@4c3um|
return -2; //-2 represent access is error f3n^Sw&Q(Q
} cUP1Uolvn
-hfkF+=U'
g"Hl 30o
String sHeader; mXhC-8P
qc.TYp
bC"h7$3
for(int i=1;;i++) i;/;zG^=_
{ )(yaX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Drf Au
//Utility.log(in.readLine()); {S-M]LE
sHeader=httpConnection.getHeaderFieldKey(i); /=l!F'
if(sHeader!=null) THX% z `
{ ^8bc<c:P
if(sHeader.equals("Content-Length")) z79oj\&[
{ 55TFBDc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6< -Cpc
break; Il>o60u1
} gBWr)R
} XYD-5pG
else 3TeRZ=2:*x
break; 7LM&3mA<
} [-"ZuUG
} gaNe\
catch(IOException e){e.printStackTrace ();} A /c
catch(Exception e){e.printStackTrace ();} uit.r^8l
-Vb5d!(
pbqk
Utility.log(nFileLength); [~cz|C#
-OmpUv-O"
=zrfh-lwH
return nFileLength; ?-o_]!*v0/
} 5kWzD'!^
0|K<$e6IH
90Sras>F
//保存下载信息（文件指针位置） vaHtWz!P
private void write_nPos() 4bdCbI
{ ps8tr:T^=
try{ 65U\;Ew
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;o;ak.dTt
output.writeInt(nStartPos.length); z<^LY]
for(int i=0;i<nStartPos.length;i++) g2^{+,/^K
{ VM&Ref4
// output.writeLong(nPos); EB}~^ aY
output.writeLong(fileSplitterFetch.nStartPos); kEAF1RP:
output.writeLong(fileSplitterFetch.nEndPos); `HYj:4v'
} Wlq3r#
output.close(); /zQx}U)TP
} c05-1
catch(IOException e){e.printStackTrace ();} |%#NA!e4wA
catch(Exception e){e.printStackTrace ();} 2u5\tp?8
} w@6y.v1I{
$\1M"a}F
XhWo~zh"
//读取保存的下载信息（文件指针位置） lt]&o0>
private void read_nPos() r58<A'#
{ car|&b
try{ 9AQ,@xP|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uTJz"c`F
int nCount = input.readInt(); $T66%wX
nStartPos = new long[nCount]; :J x%K
nEndPos = new long[nCount]; nra)t|m
for(int i=0;i<nStartPos.length;i++) ci:|x =
{ 7)2Q
nStartPos = input.readLong(); 3,*A VcQA
nEndPos = input.readLong(); 9`VY)"rJ
} B`3z(a92S
input.close(); f w)tWJVD
} r~oUln<[
catch(IOException e){e.printStackTrace ();} GiK,+M"d
catch(Exception e){e.printStackTrace ();} g3Hi5[-H
} *A}td8(
~ oq.yn/1
(Nd)$Oq[4
private void processErrorCode(int nErrorCode) H,GnF
{ <HS{A$]
System.err.println("Error Code : " + nErrorCode); (G$Q\>
} ZZ :*c"b:
O*]}0*CT
u WdKG({][
//停止文件下载 QK#qW-49O
public void siteStop() ni )G
{ xdaq` ^Bbt
bStop = true; QG L~??
for(int i=0;i<nStartPos.length;i++) t.O~RE
fileSplitterFetch.splitterStop(); 2S[:mnK
v6! `H
Rp:I&f$Hk/
} Q[H4l({E
} t%k`)p7O
//负责部分文件的抓取 4R8Qn^
**FileSplitterFetch.java ;yjw(OAI*
*/ Ro<5c_k
package NetFox; 2lN0Sf@
n<b}6L}
,qV7$u
import java.io.*; |m*l/@1
import java.net.*; 8-kR {9r
hM="9]i.
*g:Dg I 2
public class FileSplitterFetch extends Thread { Q4S:/"*v8
#KHj.Vg
opzlh@R 3
String sURL; //File URL M-+!z5q~d
long nStartPos; //File Snippet Start Position qAlX#]
long nEndPos; //File Snippet End Position P9S)7&+DL
int nThreadID; //Thread's ID gdyWuOxa|
boolean bDownOver = false; //Downing is over ka(3ONbG
boolean bStop = false; //Stop identical 43,*.1;sz
FileAccessI fileAccessI = null; //File Access interface 2'Kh>c2
=W"T=p*j
sdd%u~4,X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +I*a=qjq
{ !g|[A7<|
this.sURL = sURL; YETGq-
this.nStartPos = nStart; N PqO b
this.nEndPos = nEnd; 5dX0C
nThreadID = id; 7<2^8`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o(D_ /]'8
} (58r9WhS
cmd7-2
x%W~@_
public void run() ox";%|PP1
{ +I:/8,&-x
while(nStartPos < nEndPos && !bStop) 1NrNTBI@
{ 91fZr
lX50JJwk
QMDkkNK
try{ ,Vz-w;oDn
URL url = new URL(sURL); =dWqB&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4JH^R^O<n
httpConnection.setRequestProperty("User-Agent","NetFox"); -y$<fu9 e
String sProperty = "bytes="+nStartPos+"-"; G%}k_vi&q
httpConnection.setRequestProperty("RANGE",sProperty); {9Q**U`w
Utility.log(sProperty); O[|X=ZwR:l
9sv#TT5V
=#{q#COK$
InputStream input = httpConnection.getInputStream(); "b)EH/s
//logResponseHead(httpConnection); E429<LQI/
}p8iq
Y|KT3
byte[] b = new byte[1024]; \t=#MzjR
int nRead; &$~irI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c;#gvE
{ ,~Lx7 5{
nStartPos += fileAccessI.write(b,0,nRead); DW)81*~g
//if(nThreadID == 1) T*(mi{[T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QUz4 Kt
} =66'33l2
a`U/|[JM
<?Z]h]C^o
Utility.log("Thread " + nThreadID + " is over!"); I&% Z*H
bDownOver = true; cCG!X%9
//nPos = fileAccessI.write (b,0,nRead); uj)fah?Wg
} b<E78B+Aax
catch(Exception e){e.printStackTrace ();} 5ne&6
} !bn=b>+
} Nr*o RYY
b |ijkys
h5v=h>c
//打印回应的头信息 $+U6c~^^
public void logResponseHead(HttpURLConnection con) @F|pKf:M+
{ iBY16_q
for(int i=1;;i++) ^--8 cLB n
{ 8rLhOA
String header=con.getHeaderFieldKey(i); Xhpcu1nA
if(header!=null) IGA4"\s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i G%R'/*
Utility.log(header+" : "+con.getHeaderField(header)); UhU"[^YO
else Fj`K$K?
break; }E&:
} 4(`U]dNcs
} n8z++T&
P9jSLM
IJ7wUZp"
public void splitterStop() T^#d\2
{ ofs'xs1C
bStop = true; wVF qkJ
} TRE D_6
{r#uD5NJ/
"EZpTy}Ee
} ;Qq7@(2y
9&Z+K'$=
x+[ATZ([
/* _Ec"[xW
**FileAccess.java jcRe),
*//文件访问(定位，写) F;T;'!mb
package NetFox; V \/Qik{h
import java.io.*; 7ab'q&Y[
<00=bZzX
Rt@O@oDI
public class FileAccessI implements Serializable{ equi26jhr
UQbk%K2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O.{
RandomAccessFile oSavedFile; z]2lT IWg
long nPos; jI9#OEH_g
XQ8q)B=
Xi w
public FileAccessI() throws IOException Ydyz-
{ #];ulDq
this("",0); Uz%ynH
} 7JBr{3;eS
.0MY$0s
f*VXg[&\\F
public FileAccessI(String sName,long nPos) throws IOException E H|L1g
{ >'jkL5l
oSavedFile = new RandomAccessFile(sName,"rw"); &}\{qFD;
this.nPos = nPos; e7plL^^`
oSavedFile.seek(nPos); alBnN<UM
} :NB.ib@*
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OLoo#HW
public synchronized int write(byte[] b,int nStart,int nLen) 7G0;_f{
{ q#\B}'I{
int n = -1; J|VDZ# c7
try{ N0N%~3
oSavedFile.write(b,nStart,nLen); '}-QZ$|*
n = nLen; ubc k{\.
} qggRS)a
catch(IOException e) FtlJ3fB@
{ Xe(]4Ux
e.printStackTrace (); p&D7&Sb[
} QSwT1P'U
TP)o0U
uO1^nK
return n; +]0hSpZ"p
} Qh*}v!3Jo
K??jV&Xor
E )2/Vn2
} rje;Bf
$4og{
ft0tRv(s:
/* ~RZN+N
**SiteInfoBean.java %/ :&L+q
*/ a)7&2J
package NetFox; o@C|*TXN
5glEV`.je
Mgu9m8 `J
public class SiteInfoBean { $-<yX<.
/AYq^
k?/!`
private String sSiteURL; //Site's URL #Yy5@A}`o
private String sFilePath; //Saved File's Path `>RM:!m6=$
private String sFileName; //Saved File's Name Ec}9R3 m
private int nSplitter; //Count of Splited Downloading File q6x}\$mL
%CgmZTz~<
$#wi2Ve=6b
public SiteInfoBean() J%fJF//U
{//nSplitter的缺省值为5 i.7$~}
//default value of nSplitter is 5 P$3!4D[
this("","","",5); "cbJ{ G1pk
} !~j9Oc^
@Y+kg
QD1&"T<.d.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7 Rc/<,X
{ .'2"83f
sSiteURL= sURL; %:dd#';g
sFilePath = sPath; QX_![|=
sFileName = sName; !A14\
this.nSplitter = nSpiltter; e$mVA}>Ybp
j-qg{oIJ
]eTp?q%0
} d[E= HN
ZY;g)`E1
rERtOgi
public String getSSiteURL() YYvX@f
{ $-E<{
return sSiteURL; UY:Be8C A
} +RK/u
f,BJb+0
B E#pHg
public void setSSiteURL(String value) :MH=6
{ x26 sH5
sSiteURL = value; 472'P
} D^{jXNDNO
Gr3 q
9(bbV5}
public String getSFilePath() (8em5
{ cc"<H}g>`
return sFilePath; p%OVl[^jp
} "{jVsih0
&3*r-9BZ
-{yG+1
public void setSFilePath(String value) E,4*a5Fi
{ YKx+z[A/p
sFilePath = value; BpF}H^V-
} y!j>_m){w
qtP*O#1q
Pfm B{
public String getSFileName() zS?DXE
{ _G)x\K]N
return sFileName; J/[PA[Rf
} O:dUzZR['
zK*i:(>B
t"6u
public void setSFileName(String value) \,`iu=YZv
{ e"2x!(&n(
sFileName = value; wJ7Fnj>u%
} @_h=,g#@
*#'&a(hB!
tTJ$tx
public int getNSplitter() V("T9g
{ t1aKq)?
return nSplitter; |@)jS.Bn
} AgdU@&^
NV`7VYU
r\} O{ZO
public void setNSplitter(int nCount) cP0(Q+i7
{ JOki4N
nSplitter = nCount; k:1|Z+CJ
} w1= f\
} 'EkjySZ]F{
0fR?zT?
z'EphL7r
/* q4u-mM7#7
**Utility.java NbUibxJ
*/ :NWrbfz
package NetFox; #YLI"/Kn
c$)!02
A2B]E,JMp
public class Utility { }z2K"eGt
xllmF)]*Y
t%Y}JKLR
public Utility() N3Z6o.k
{ SS-7y:6y>
f<@`{oP@
0U:9&jP,
} o31pF
<9?`zo$y
//线程睡眠 *&W1|Qkg_
public static void sleep(int nSecond) 4&E&{<;
{ 97VS xhr
try{ K.6xNQl{}
Thread.sleep(nSecond); -O[9{`i]
} l' a<k"
catch(Exception e) .A<n2-
{ 0 oHnam
e.printStackTrace (); Uj~ :|?Wz
} ,wk %)^
} u[coWaPsZ
Iy{&T#e"
//日志 <:`x> _
public static void log(String sMsg) #^<Rx{
{ 8x<; AL|`
System.err.println(sMsg); }m-+EUEo9
} |",/
},tn
7j\jOklV
public static void log(int sMsg) tje
{ Q 1e hW
System.err.println(sMsg); ~ny4Ay$#
} ;=?KQq f
} `n~bDG>
'B$qq[l]S
\Y}nehxG@
/* ai(J%"D"
**TestMethod.java /s^O M`5
*/ AP_2.V=Sn
package NetFox; 9WsGoZPn
!3#*hL1fy
<YBA 7i
public class TestMethod { NhA_dskvo
BF>3CW7
N6_<[`
public TestMethod() 7\1bq&a<
{ ///xx/weblogic60b2_win.exe /I3>u
try{ 4V0j1k&'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <xQHb^:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O(oGRK<xM
SiteFileFetch fileFetch = new SiteFileFetch(bean); RA~%Cw4t
fileFetch.start(); t9B]V
} ]za1=~[
catch(Exception e){e.printStackTrace ();} N!&$fhY)
6?v)Hb}J%d
<kr%ylhIu
} W{2(fb
(lY<\l
Ou<Vg\Mu
public static void main(String[] args) amK.H"
{ e8"?Qm7 J
new TestMethod(); F&om^G'U
} &\, ZtaB
} ^q0Ox&X
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