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)); |OVD*A
} +|OrV'
for(int i=0;i<nEndPos.length-1;i++) NR@n%p
{ }o{6
nEndPos = nStartPos[i+1]; .on}F>3k$
} {rE]y C^
nEndPos[nEndPos.length-1] = nFileLength; >i:hdcxe
} G|,'6|$jE
} F/(z3Kf
O&(@Ka
sfuA {c'v
//启动子线程 ]>%M%B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XSDudL
for(int i=0;i<nStartPos.length;i++) _+?v'#
{ Qjl.O HO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]DV=/RpJ9B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +:#x!i;W8[
nStartPos,nEndPos,i); v_s(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Gi9s*v,s
fileSplitterFetch.start(); *|F ;An.N^
} ~Y3"vdd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MPxe|Wws
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h+<F,0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {:!CA/0Jx
nEndPos = " + nFileLength); Eqc,/
// fileSplitterFetch[nPos.length-1].start(); wFHbz9|@I
rcx'`CIJ
F\"`^`(O
//等待子线程结束 yo=0Ov
//int count = 0; x+V@f~2F
//是否结束while循环 PE7D)!d T
boolean breakWhile = false; fZ6"DJZ
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sERm+x<
while(!bStop) c&rS7%
{ VBe.&b8
write_nPos(); &|8R4l C|
Utility.sleep(500); )?zlhsu}1;
breakWhile = true; <Jwx|
>I^_kBa
[fjP.kw;J
for(int i=0;i<nStartPos.length;i++) ( ;(DI^Un8
{ dRXEF6G
if(!fileSplitterFetch.bDownOver) FWJhi$\:D]
{ .dvOUt I[
breakWhile = false; +uD4$Wt_F
break; p+pBk$4
} BIM!4MHLA
} "{igrl8
if(breakWhile) vXP+*5d/ K
break; =8!FY"c*
Munal=wL
3gcDc~~=
//count++; F4|Z:e,Hr
//if(count>4) v.~uJ.T
// siteStop(); 8qi6>}A
} 6bXP{,}Gp
TjswB#
<8[y2|UBt
System.err.println("文件下载结束！"); wP: w8O
} rCTH 5"
catch(Exception e){e.printStackTrace ();} l)^sE)
} 'Rg6JW\
"Om4P|
pm 4"Q!K
//获得文件长度 c%bGVRhE
public long getFileSize() (*CGZDg
{ w.2[Xx~
int nFileLength = -1; 9jC>OZ0s
try{ +"HLx%k
URL url = new URL(siteInfoBean.getSSiteURL()); F}C.F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TcP (?v
httpConnection.setRequestProperty("User-Agent","NetFox"); >2%*(nL
`BA,_N|6
K\2UwX
int responseCode=httpConnection.getResponseCode(); ;:/<XfZ
if(responseCode>=400) !pMp n%r<]
{ k ='c*`IE
processErrorCode(responseCode); 2Kg+SLU[~
return -2; //-2 represent access is error [!k#au+#c
} 4-wCk=I
l^$8;$Rq
PI5a'k0F
String sHeader; Y4 <
XC D&Im
-hpJL\ng
for(int i=1;;i++) P`$"B0B)
{ yL#bZ9W }
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~}g"Fe
//Utility.log(in.readLine()); hA0g'X2eC
sHeader=httpConnection.getHeaderFieldKey(i); g+xA0qW
if(sHeader!=null) 06dk K)`
{ >kLUQ%zE@
if(sHeader.equals("Content-Length")) "{&?t}rj+
{ j=Co
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); < SIe5"{
break; !|1GraiS
} s?JNc4q
} n.a55uy
else jQgy=;?Lwm
break; 1syI%I1
} :k"VR,riF
} j%V95M%$
catch(IOException e){e.printStackTrace ();} Gh:hfHiG
catch(Exception e){e.printStackTrace ();} r@XH=[:
_eE hIQ9
z'(][SB
Utility.log(nFileLength); J!5>8I(_wX
8)1k>=
(1|_Nr
return nFileLength; V\ 7O)g
} C]xKdPQj%
Y@+e)p{
YXdd=F
//保存下载信息（文件指针位置） KqE5{ q
private void write_nPos() BJ]4j-^o
{ :JEzfI1
try{ k!^Au8Up?
output = new DataOutputStream(new FileOutputStream(tmpFile)); BM@:=>ypQ
output.writeInt(nStartPos.length); NFEF{|}BM
for(int i=0;i<nStartPos.length;i++) -S ASn
{ |K H&,
// output.writeLong(nPos); is2OJ,
output.writeLong(fileSplitterFetch.nStartPos); n&51_.@Q
output.writeLong(fileSplitterFetch.nEndPos); JS&=V67[
} _"Bh 3 7
output.close(); :ziV3jRM
} O=9mLI6
catch(IOException e){e.printStackTrace ();} =Z($n:m=*
catch(Exception e){e.printStackTrace ();} + \DGS
} ?/SIA9VK
{5$.:Y
U1Z.#ETnM
//读取保存的下载信息（文件指针位置） RO]Vn]qb
private void read_nPos() \R6D'Yt
{ 8w:A""
try{ R43yr+p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^hpdre"
int nCount = input.readInt(); aQzu[N
nStartPos = new long[nCount]; +8rGStv
nEndPos = new long[nCount]; #-0}r
for(int i=0;i<nStartPos.length;i++) 0&YW#L|J
{ ^Ia:e ?)W
nStartPos = input.readLong(); ~BSIp .
nEndPos = input.readLong(); ;~2RWj=-
} w=UFj
input.close(); sn4wd:b7%
} d^0vaX6e}
catch(IOException e){e.printStackTrace ();} &<s[(w!%%
catch(Exception e){e.printStackTrace ();} x/UmpJD+
} ?D6?W6@
c%5G3j
&Ow[
private void processErrorCode(int nErrorCode) z/B[quSio
{ aQMUC6cPM@
System.err.println("Error Code : " + nErrorCode); K!JXsdHK
} J`&*r;""V
3XCePA5z
(zVT{!z
//停止文件下载 v*Fr#I0U
public void siteStop() * mzJ)4A
{ Stzv
bStop = true; Z|8oD*,
for(int i=0;i<nStartPos.length;i++) WB:NV=&^
fileSplitterFetch.splitterStop(); '_f]qNy
8f""@TTp
JDQ7
} ot"3 3I
} Y5 BWg
//负责部分文件的抓取 gJkk0wokC
**FileSplitterFetch.java W'>"E/Tx#O
*/ yJ\K\\]
package NetFox; *?'^Rc
V<ZohB?y
K,!"5WrX*
import java.io.*; W+F^(SC\
import java.net.*; u9TiEEof3
, ;'y <GA
eQiK\iDS
public class FileSplitterFetch extends Thread { IfeCSK,x
-v'|#q
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String sURL; //File URL ewOd =%
long nStartPos; //File Snippet Start Position Rh[%UNl
long nEndPos; //File Snippet End Position _y,?Cj=u|
int nThreadID; //Thread's ID Nq$Xe~,*
boolean bDownOver = false; //Downing is over q_h=O1W
boolean bStop = false; //Stop identical deRnP$u0
FileAccessI fileAccessI = null; //File Access interface cZd9A(1"^
@w8MOT$
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n<}t\<LG^c
{ 1Qc>A8SU
this.sURL = sURL; h!vq~g
this.nStartPos = nStart; *8ZaG]L
this.nEndPos = nEnd; e^N6h3WF
nThreadID = id; cgQ4JY/6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 N8]DW_bsB
} kM#ZpI&0%
`t@Rh~B
Pjs L{,
public void run() :o)4Y
{ l,I[r$TCf
while(nStartPos < nEndPos && !bStop) 8&g`Uy/b
{ lg9`Z>?
9S.J%*F7
;tBc&LJ?
try{ WOv m%sX
URL url = new URL(sURL); {^Y0kvnd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *!~jHy8F
httpConnection.setRequestProperty("User-Agent","NetFox"); O&]P u5
String sProperty = "bytes="+nStartPos+"-"; ,?'":T1[
httpConnection.setRequestProperty("RANGE",sProperty); cZ<@1I5QK
Utility.log(sProperty); D2060ze
9r5<A!1#L
]*M VVzF
InputStream input = httpConnection.getInputStream(); f _ O
//logResponseHead(httpConnection); X\Y:9^5
zqDG#}3f^
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byte[] b = new byte[1024]; p$qpC$F
int nRead; c{qoASc?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x#-+//
{ vE}>PEfA
nStartPos += fileAccessI.write(b,0,nRead); 1ymq7F(2
//if(nThreadID == 1) Hn-k*Y/P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SR+<v=i
} /^m3?q[a
n1"QHA
[K*>W[n
Utility.log("Thread " + nThreadID + " is over!"); X-Yy1"6m1
bDownOver = true; e>OYJd0s
//nPos = fileAccessI.write (b,0,nRead); g9rsw7
} I3#h
catch(Exception e){e.printStackTrace ();} q h+c}"4m
} gz,x6mnQ
} ~> xVhd
=:4vRq [
jkN-(v(T
//打印回应的头信息 b<1k$0J6
public void logResponseHead(HttpURLConnection con) nB8JdM2h{
{ -F]0Py8(
for(int i=1;;i++) cAL*Md8+
{ "TLY:V
String header=con.getHeaderFieldKey(i); n#NE.ap$&,
if(header!=null) ?HsQ417.H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]]InD N
Utility.log(header+" : "+con.getHeaderField(header)); 7AOjlC9R}
else 2I!L+j_
break; Uu<Tn#nb
} "EE=j$8u+
} wG,"ZN
S~Z`?qHWh
pE^jUxk6
public void splitterStop() ZeL v!
{ h=1cD\^|qw
bStop = true; NIzxSGk|
} 3RW3<n
HxH.=M8S_
m9&MTRD\
} #VLO6
RfZZqeU
G;'=#c ^
/* _(TYR*
**FileAccess.java SviGLv;oR
*//文件访问(定位，写) UTThl2=+
package NetFox; `akbzHOM
import java.io.*; " iKX-VIl
TqZ&X|G
a9w1Z4
public class FileAccessI implements Serializable{ ^EG@tB $<
.t7mTpi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X-Q;4M-CJ
RandomAccessFile oSavedFile; LHS^[}x^1
long nPos; kJOSGrg
lwhVP$q}
clcj5=:
public FileAccessI() throws IOException [xrM){ItW
{ 7wm9S4+|
this("",0); EE^ N01<"\
} HoFFce7o
9AbSt&#
mHnHB.OL
public FileAccessI(String sName,long nPos) throws IOException itp$c|{
{ o C5}[cYD`
oSavedFile = new RandomAccessFile(sName,"rw"); M< T[%)v
this.nPos = nPos; d- wbZ)BR
oSavedFile.seek(nPos); ub#>kCL9
} Ao%;!(\I%
T9c=As_EM
#]BpTpRAe<
public synchronized int write(byte[] b,int nStart,int nLen) w'Cn3b)`
{ f\Fk+)e@
int n = -1; Ke_&dgsq
try{ S!/N lSr<
oSavedFile.write(b,nStart,nLen); :=0XT`iY
n = nLen; v7L}I[f
} <MPoDf?h
catch(IOException e) z_jTR[dY
{ \mBH6GS
e.printStackTrace (); dZ kr#>
} \[-z4Fxg|'
#*g.hL<
=t+{)d.w
return n; Hko(@z
} T}?vp~./
4/Vy@h"A3
zW@OSKq4
} ""dX4^gtU
'pUJlPGx
0'DlsC/`*
/* ATeXOe
**SiteInfoBean.java V!'N:je
*/ 3,snx4q (
package NetFox; e<wRA["
O$><E8q
G]Jchg <
public class SiteInfoBean { S+i .@N.^
"!yKX(aTX
&zCqF=/9U
private String sSiteURL; //Site's URL No\H QQ
private String sFilePath; //Saved File's Path =,aWO7Pz
private String sFileName; //Saved File's Name doCWJ
private int nSplitter; //Count of Splited Downloading File fs]9HK/@\
,|: a7b]
/12D >OK
public SiteInfoBean() A2`QlhZ
{//nSplitter的缺省值为5 XsldbN^6
//default value of nSplitter is 5 2u[:3K-@,
this("","","",5); u@`)u#
} >`jsUeS
%j].' ;
+[ _)i9a
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u}QB-oU
{ eQk ~YA]K
sSiteURL= sURL; kRs24=
sFilePath = sPath; {__Z\D2I
sFileName = sName; xM1>kbo|
this.nSplitter = nSpiltter; Z=O2tR
ILUA'T=B0
E"Z9 NDgl#
} :E|HP#iwu
r<;bArs-u
9Z0(e!b4S
public String getSSiteURL() \/jr0):
{ "y>\ mC
return sSiteURL; @:@0}]%z9
} u7u8cVF
8Ek<J+&|I
R v9?<]
public void setSSiteURL(String value) XA~Rn>7&H
{ D[)")xiG
sSiteURL = value; 4C(vBKl
} -ob_]CKtJ~
[y y D-
5_+vjV;5
public String getSFilePath() ^4Ra$<
{ 'sJ=h0d_[V
return sFilePath; (Rvke!"B
} zCD?5*7
c'_-jdi`>_
/"?y @;Y~
public void setSFilePath(String value) w>T1D
{ b=a&!r5M
sFilePath = value; ?H7*?HV
} *LeFI%
Ebp^-I9.d
E|D~:M%~
public String getSFileName() ^RG6h
{ 8WU UE=p
return sFileName; QP|Ou*Qm)
} 'v4#mf
buGW+TrWY
St&xe_:^<
public void setSFileName(String value) L)VEA8}
{ fGJPZe
sFileName = value; ]{Vq;
} {*H&NI
I#Ay)+D
KzZ! CB\
public int getNSplitter() Y((s<]7
{ Nm%&xm
return nSplitter; T[s_w-<7$
} &|u
!o 2"th
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public void setNSplitter(int nCount) [AQ6ads)
{ z %` \p
nSplitter = nCount; A!s\;C
} -;'8#"{`^
} %\=5,9A\
}% JLwN
elb|=J`M0
/* 9H?er_6Yf
**Utility.java $x 6Rmd{
*/ F{ J>=TC
package NetFox; #gi0FXL
3N(s)N_P M
r#*kx#"
public class Utility { >- ]tOH,0
q5?g/-_0[
(=0W[@k
public Utility() `h_,I R<
{ +ZtqR
=2pGbD;*
DCM,|FE
} zx'G0Z9]
|{+D65R
//线程睡眠 MPA<?
public static void sleep(int nSecond) CL|t!+wU/
{ H1rge<
try{ ii0AhQ
Thread.sleep(nSecond); <i"U%Ds(
} 5#s?rA%u
catch(Exception e) s/UIo^m
{ ;$l!mv7
e.printStackTrace (); 5i7,s
} A:ls'MkZ4
} <splLZW3k
~"!F&
//日志 zg2A$Fd[j
public static void log(String sMsg) v5i[jM8
{ \ }>1$kH;
System.err.println(sMsg); gBUtv|(@>[
} #ebT$hf30
DtG><g}[]
|[(4h
public static void log(int sMsg) Um]>B`."wK
{ EC$wi|i
System.err.println(sMsg); kX."|]
} A;m)/@
} !L:!X88
p{xO+Nx1a
dbSIC[q
/* sguE{!BO
**TestMethod.java !/ TeTmo
*/ ,.uu/qV}w
package NetFox; > nY<J
%@3AA<
.9+"rK}u
public class TestMethod { Brr{iBz*"
5_ -YF~
5t#+UR
public TestMethod() G$XvxJ
{ ///xx/weblogic60b2_win.exe VlRN
try{ >Jt,TMMlt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yjvzA|(YC
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dX{|-;6vm
SiteFileFetch fileFetch = new SiteFileFetch(bean); hH[UIe
fileFetch.start(); z kQV$n{
} m619bzFlB
catch(Exception e){e.printStackTrace ();} 9KRHo%m
~Wjm"|c
&1YqPk
} I>o+INb:
a'U7 t
=`[08
public static void main(String[] args) )(~4fA5j)
{ T`7;Rl'Q
new TestMethod(); akHcN]sa2
} h 1G`z
} 0b+OB pqN
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