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)); lD_iIe~c
} l#w0-n%S
for(int i=0;i<nEndPos.length-1;i++) bZQ_j#{$
{ #a8i($k{e
nEndPos = nStartPos[i+1]; 1OqVNp%K
} f_hG2Sk
nEndPos[nEndPos.length-1] = nFileLength; $m+Pl[s
} *_Pkb.3R
} jlUT9Zp
8jLO-^X<<
s>>lf&7
//启动子线程 ,d=Dicaz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b+CvA(*
for(int i=0;i<nStartPos.length;i++) gKPqU@$*
{ Zyz)`>cB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iq8Hq)I]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *s2 C+@ef
nStartPos,nEndPos,i); 1'k,P;s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =)Goip
fileSplitterFetch.start(); ::/vDUDc
} dGR #l)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), IY(;:#l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SQuW`EHBgs
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t +CU
nEndPos = " + nFileLength); IueI7A
// fileSplitterFetch[nPos.length-1].start(); x_4{MD^%
)$2h:dw_
g%4=T~
//等待子线程结束 n0^3F1Z
//int count = 0; [ID#PUle
//是否结束while循环 -#AO4xpI
boolean breakWhile = false; 3[m~6Ys
4'`*Sce}
|qq29dS?
while(!bStop) cavzXz
{ 4&`d$K
write_nPos(); {?IUf~<
Utility.sleep(500); bGB5]%v,
breakWhile = true; zn\$6'"
).$kp2IN
2QIo|$
for(int i=0;i<nStartPos.length;i++) VZA>ErB
{ FvBnmYnW
if(!fileSplitterFetch.bDownOver) 7{f{SIB
{ GIUyW
breakWhile = false; tZD^<Q7}\
break; v #Q(g/^
} TiI3<.a!
} 42DB0+_wz
if(breakWhile) 0Jm)2@
break; "LVN:|!
]5eZLXM
yfe4}0}
//count++; 0:>C v<N
//if(count>4) Yp9%u9tNq
// siteStop(); _qS4Ns/4s
} .OF2O}
uF-Rl## >
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System.err.println("文件下载结束！"); ,aSK L1
} sRGIHT#
catch(Exception e){e.printStackTrace ();} V"sm+0J
} 5U JMiwP{
k=5v J72U
t$U eks
//获得文件长度 +r__>V,
public long getFileSize() 5cC)&}I
{ %0eVm
int nFileLength = -1; p{rzP,Pb&
try{ _,|N`BBqd
URL url = new URL(siteInfoBean.getSSiteURL()); a[V4EX1E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i}ti
httpConnection.setRequestProperty("User-Agent","NetFox"); s#)tiCSVW
6C*4' P9>
jR,3-JQ
int responseCode=httpConnection.getResponseCode(); dv\aP
if(responseCode>=400) f<2<8xS
{ G%fNGQwT
processErrorCode(responseCode); Kdb:Q0B
return -2; //-2 represent access is error ^g N?Io
} s!K9-qZl<
0Y ld!L
(k5d.E]CK
String sHeader; 3VmF1w 2
1?ST*b
DUu~s,A
for(int i=1;;i++) 1BA5|
{ P;lDri
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >]l7AZ:,
//Utility.log(in.readLine()); e{IwFX
sHeader=httpConnection.getHeaderFieldKey(i); :.NCS`z_
if(sHeader!=null) hc5iIJ]
{ AU H_~SY
if(sHeader.equals("Content-Length")) ln=:E$jX
{ YU%U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L)/^%/!
break; ]Saw}agE[%
} [%BWCd8Q~P
} P}bwEj
else FKu^{'Y6E0
break; /hbdQm
} Ng<oz*>U
} H}&4#CQ'!
catch(IOException e){e.printStackTrace ();} TY*q[AWG
catch(Exception e){e.printStackTrace ();} &+F}$8,
W!WeYV}kb
1jQlwT(:
Utility.log(nFileLength); eWAgYe2
BZWGXzOFh
:jioF{,
return nFileLength; ZuQ\Pyx
} +^@6{1
"+KAYsVtU
/s~&$(d59o
//保存下载信息（文件指针位置） \I`g[nT|
private void write_nPos() e't1.%w
{ .2:S0=xt<
try{ Z?tw#n[T
output = new DataOutputStream(new FileOutputStream(tmpFile)); F6 c1YI[
output.writeInt(nStartPos.length); 8&KqrA86
for(int i=0;i<nStartPos.length;i++) ]u@`XVEJ
{ pj9s=}1 '
// output.writeLong(nPos); ,O]AB
output.writeLong(fileSplitterFetch.nStartPos); 2*@.hBi
output.writeLong(fileSplitterFetch.nEndPos); ?o6\>[O
} CaqMLi%
output.close(); 1q;r4$n
} l>:\% ol
catch(IOException e){e.printStackTrace ();} wZ =*ejo
catch(Exception e){e.printStackTrace ();} K+J fU J
} ~'L`RJR
E'4dI:
:\8&Th}Se
//读取保存的下载信息（文件指针位置） 66shr
private void read_nPos() ,2_!hm/
{ @jevY81)
try{ %oEvp{I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x$\w^h\F
int nCount = input.readInt(); /0I=?+QSo
nStartPos = new long[nCount]; ~`Xu6+1o
nEndPos = new long[nCount]; xKC{P{:
for(int i=0;i<nStartPos.length;i++) @Tg+Kt
{ eMV@er|
nStartPos = input.readLong(); 8|iMD1
nEndPos = input.readLong(); tM;S )S(=
} P_3U4J
input.close(); G`r*)pdm
} QHuh=7u)
catch(IOException e){e.printStackTrace ();} E?Ofkc$q
catch(Exception e){e.printStackTrace ();} JqmKD4p
} /Jci1o
9 ]W4o"
w_eUU)z
private void processErrorCode(int nErrorCode) "sU ~|
{ [O"8Tzr
System.err.println("Error Code : " + nErrorCode); `OmYz{*r
} L=WB'*N
0al8%z9e@
GcYT<pwN6
//停止文件下载 :Y;\1J<b1
public void siteStop() LQrm/)4bF5
{ Ghpk0ia%d
bStop = true; ,HM~Zs
for(int i=0;i<nStartPos.length;i++) [r5k8TB1
fileSplitterFetch.splitterStop(); Jz6,2,LN
'}q1 F<&
%/x%hs;d
} FI$#x%A
} Tx'ctd#Y
//负责部分文件的抓取 N$SJK
**FileSplitterFetch.java h8lI#Gs
*/ pe1_E KU
package NetFox; B 8ycr~
I!1nB\l
Y2,\WKa
import java.io.*; $"&U%3
import java.net.*; aY7.<p*a
H;OPA8\n
b_JW3l
public class FileSplitterFetch extends Thread { )c$)am\I{
>av.pJ(>
';z5]O~
String sURL; //File URL -'OO6mU
long nStartPos; //File Snippet Start Position NJglONO
long nEndPos; //File Snippet End Position h8MkfHH7{
int nThreadID; //Thread's ID ]XH}G9X^
boolean bDownOver = false; //Downing is over JrdH6Zg
boolean bStop = false; //Stop identical ].eY]o}=
FileAccessI fileAccessI = null; //File Access interface )tV^)n[w
Z|kMoB
>O{/%(9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uF=xo`=|
{ yNb :zoT
this.sURL = sURL; sC .R.
this.nStartPos = nStart; {PCf'n
this.nEndPos = nEnd; nBVknyMFNF
nThreadID = id; !7K-Kqn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xf.2Ig
} >xt*(j&}
MXxE)"G*a
P00pSRQHD
public void run() K{&b "Ba1
{ Xkv+"F=-
while(nStartPos < nEndPos && !bStop) Qb|.;_
{ CXsi
h8yv:}XU*
.ZxH#l _
try{ 9$xEktfV
URL url = new URL(sURL); plY`lqm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *0^t;A+
httpConnection.setRequestProperty("User-Agent","NetFox"); '*KP{"3\
String sProperty = "bytes="+nStartPos+"-"; DjT ekn
httpConnection.setRequestProperty("RANGE",sProperty); M\s^>7es
Utility.log(sProperty); -0)So
~"*;lT5KX
-e{H8ro
InputStream input = httpConnection.getInputStream(); pw7_j;}l
//logResponseHead(httpConnection); UI4Xv
Vo%UiVHy
diLjUC`69
byte[] b = new byte[1024]; ,QpDz{8
int nRead; A_t<SG5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O;A/(lPW+
{ ]rh)AE!Y(
nStartPos += fileAccessI.write(b,0,nRead); "iof -b=ys
//if(nThreadID == 1) 8bX\^&N
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \?} {wh8
} &\C{,:[
[^gSWU
bz~-uHC
Utility.log("Thread " + nThreadID + " is over!"); _l?5GLl_F$
bDownOver = true; f-\l<o(
//nPos = fileAccessI.write (b,0,nRead); Zv=p0xH
} ]'aGoR
catch(Exception e){e.printStackTrace ();} -BV&u(
} g(:y_EpmLH
} B%Yb+M&K
a<V=C
S)"5X)mq
//打印回应的头信息 |7zm!^t$
public void logResponseHead(HttpURLConnection con) >NwrJSx
{ u%O^hcfb
for(int i=1;;i++) fxLhVJ"b
{ `,(1'
String header=con.getHeaderFieldKey(i); %;9eh'
if(header!=null) ZUyM:$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zYOPE 6E
Utility.log(header+" : "+con.getHeaderField(header)); n20H{TA
else IBVP4&}x$
break; -}UCdaQ3
} 0zpP$q$
} ,Z%!38gGsu
[,5clR=F
-X4`,0y%{O
public void splitterStop() GX_Lxc_<f
{ {\t:{.F A
bStop = true; q9Y0Lk
} UhCd,
E"Xi
=]E1T8|
} YA^9, q6u?
N13 <!QQ
&TbnZnv
/* !wrl.A/P
**FileAccess.java Dz)bP{iq"
*//文件访问(定位，写) oRu S_X
package NetFox; A|>a Gy
import java.io.*; ]-.Q9cjc$q
73xI8
Zt` ,DM
public class FileAccessI implements Serializable{ xs &vgel>
,75,~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l!iB -?'u
RandomAccessFile oSavedFile; kd\yHI9A
long nPos; Mdwh-Cis/
!s)2H/KM8
"E2 g7n&
public FileAccessI() throws IOException . ~|^du<X
{ 0t4i'??
this("",0); F"23>3
} v!`M=0k
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"Pys3=h
public FileAccessI(String sName,long nPos) throws IOException "Ln\ZYB]
{ C1G Wi4)
oSavedFile = new RandomAccessFile(sName,"rw"); SwP h-6
this.nPos = nPos; b'-gy0
oSavedFile.seek(nPos); M(3E b;`
} 6 *8Ge
gieX`}
U |4%ydG
public synchronized int write(byte[] b,int nStart,int nLen) *gT TI;:
{ i&LbSxUh9
int n = -1; 98O z
try{ U3U eTa_
oSavedFile.write(b,nStart,nLen); x@k9]6/zs
n = nLen; b`:Eo+p
} fCVSVn"o
catch(IOException e) jN {ED_
{ b'{D4/
e.printStackTrace (); YT:5J%"
} .HtDcGp
uPp(l4(+
*@Qt*f
return n; v^E5'M[A
} oL6_Ya
3> fuH'=
ja>Tnfu
} [D?E\Nkk
er<~dqZ}]
(Pu*[STTT
/* G/`_$ c
**SiteInfoBean.java iCEX|Tj;
*/ i/Hi
package NetFox; ?QMs<
-zTeIvcy5
E|fPI u
public class SiteInfoBean { (p2a{v}fEz
w\QpQ~OX
[,e_2<
private String sSiteURL; //Site's URL 4i19HD_
private String sFilePath; //Saved File's Path @O(\TIg
private String sFileName; //Saved File's Name ``\H'^{B
private int nSplitter; //Count of Splited Downloading File 7:;V[/
~p 1y+
r:o!w7C:a
public SiteInfoBean() \4&g5vE
{//nSplitter的缺省值为5 oyd{}$71d
//default value of nSplitter is 5 m8f_w
this("","","",5); U--ER r8
} [zfGDMG&
KVntBe]I
NSkI2>+P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P6?Q;-\q0
{ w7W-=\Hvh
sSiteURL= sURL; #nd,cn
sFilePath = sPath; &,)tD62s
sFileName = sName; :H87x?e[
this.nSplitter = nSpiltter; :=8vy
RU'J!-w{
1hN! 2Y:
} _1Eyqh`oh
ls5S9R 5
MWuVV=rd8a
public String getSSiteURL() "N;|~S)w!
{ S,v`rmI
return sSiteURL; BZBsE :(F
} WV% KoM,%
g?`J,*y
I F@M
public void setSSiteURL(String value) *Zvw&y*
{ x{- caOH
sSiteURL = value; *SW,pHYnLb
} @PI\.y_w
(/Mc$V
6 qq7:
public String getSFilePath() Em7q@
{ 8?$2;uGL
return sFilePath; jL8zH
} /IC'R"V a
Zry>s0
7MfT~v
public void setSFilePath(String value) Y `{U45
{ q}!4b'z^
sFilePath = value; c'6H@m#=
} x<l1s
}B5I#Af7
PX'LN
public String getSFileName() 2Ar<(v$
{ zaZnL7ZJX
return sFileName; RD4)NN6y5}
} 40<&0nn
u%pief
8%4`Yj=
public void setSFileName(String value) EI;\of2,
{ %L/=heBBd
sFileName = value; (pmo[2kg
} q2Kn3{
EDo (
|h7v}Y
public int getNSplitter() H07j&
{ |}`5<a!6U
return nSplitter; 5c"kLq6r
} E;qwoTmul
1bBK1Uw
qEAF!iB]L
public void setNSplitter(int nCount) 5-OvPTY`M
{ HZ}*o%O
nSplitter = nCount; I?>#neHc6
} <%z/6I Af|
} B4}XK=)
Y[!a82MTzn
]Q3Gj@6
/* 8VZ-`?p
**Utility.java zCHr
*/ p{rS -`I
package NetFox; xeI{i{8
2]+.8G7D%
-)oBh
public class Utility { a5-\=0L~
my1kF%?
T?Y\~.+99
public Utility() ng*%1;P
{ IfcFlXmt2
,<1*
6"7qZq
} z'lNO| nU
Ro<kp8
//线程睡眠 aW"!bAdx`,
public static void sleep(int nSecond) zjA/Z(
{ c #kV+n<
try{ *3$,f>W^
Thread.sleep(nSecond); HhvG#Sam!
} {<kG{i/
catch(Exception e) z(3"\ ^T
{ 8|({ _Z
e.printStackTrace (); MxRU6+a
} D@^ZpN8r
} uNbA>*c4M
/<0D E22
//日志 $T6Qg(p
public static void log(String sMsg) qR qy
{ WM"^#=+$
System.err.println(sMsg); I*}#nY0+
} Ct)MvZ
sh ;uKzQ
3ZlI$r(
public static void log(int sMsg) &r%*_pX
{ oui!fTy
System.err.println(sMsg); L2'd sOn
} :2E1aVo4b
} j&A3s{S4A
opMUt,4
KIo}Gd&
/* >Mw &Tw}o
**TestMethod.java #ja`+w}
*/ P0xLx
package NetFox; !dY:S';~
bZ.N7X PH
+ZKhmb!
public class TestMethod { *Xoscc
d|]O<]CG_
K;[%S
public TestMethod() AxlFU~E4
{ ///xx/weblogic60b2_win.exe GYC&P]
try{ #OWs3$9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A[kH_{to;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v9U(sEDq
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6;cY!
fileFetch.start(); Da[C'm=
} wy{>gvqK
catch(Exception e){e.printStackTrace ();} ,g_onfY
u!o]Co>
NRisr
} X5Y `(/V
e({fY.)SGo
S2E HmE&
public static void main(String[] args) PuCDsojclh
{ 4|N\Q=,
new TestMethod(); o^Ysp&#p
} 61W/BU7O
} hG7S]\N_
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