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)); #fn)k1
} ,M ^<CJ
for(int i=0;i<nEndPos.length-1;i++) @O^6&\s>
{ dE{dZ#Jfi
nEndPos = nStartPos[i+1]; ]Ntmy;Q
} jkF^-Up.
nEndPos[nEndPos.length-1] = nFileLength; =R$u[~Xl2X
} @>Km_Ax
} -Cc^d!::
^Q?
CU2*z(]&
//启动子线程 _H7x9 y=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #( 146
for(int i=0;i<nStartPos.length;i++) '$]97b7G
{ >$/>#e~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O)n~](sC\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9gK`E
nStartPos,nEndPos,i); M\Ye<Tk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HJ[cM6$2
fileSplitterFetch.start(); uo%)1NS!
} rlSeu5X6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~ =2PU$u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x@;m8z0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4yr'W8X_
nEndPos = " + nFileLength); ywmo#qYe
// fileSplitterFetch[nPos.length-1].start(); 6HWE~`ok6
`%"\@<
#r~# I}U
//等待子线程结束 (2E\p
//int count = 0; '/p/8V.O.
//是否结束while循环 .:%0E`E
boolean breakWhile = false; Zaf:fsj>
jZkcBIK2
aP@N)"
while(!bStop) [uN? ~lp\%
{ =ToyZm\
write_nPos(); q01wbO3-"
Utility.sleep(500); h_3E)jc
breakWhile = true; fW1CFRHH
! Y~FLA_
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for(int i=0;i<nStartPos.length;i++) CXx*_@}MU
{ \\H}`0m:
if(!fileSplitterFetch.bDownOver) '"/=f\)u
{ ?(F6#"/E
breakWhile = false; ,pQZ@I\z
break; ;)z:fToh
} k&vz7Q`T
} 2,b(,3{`4:
if(breakWhile) BLf>_bUk
break; DGn;m\B
;~ $'2f~U
tOd&!HYL
//count++; m6\E$;`
//if(count>4) +RMSA^
// siteStop(); qUW! G&R
} ;LPfXpR
G3vxjD<DMW
oC: {aK6\
System.err.println("文件下载结束！"); )|R)Q6UJ
} t[;LD_
catch(Exception e){e.printStackTrace ();} 5o'FS{6U
} U!?_W=?
'/n1IM$7
;yLu R
//获得文件长度 l<LP&
public long getFileSize() (!7sE9rP
{ "W7K"=X
int nFileLength = -1; bL+_j}{:N
try{ RSyUaA
URL url = new URL(siteInfoBean.getSSiteURL()); l\!fj#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r,1!?s^L
httpConnection.setRequestProperty("User-Agent","NetFox"); }mYx_=+VX
)D5"ap]fX
$m{:C;UH
int responseCode=httpConnection.getResponseCode(); vzs)[AD
if(responseCode>=400) BB!THj69a6
{ Fg5kX
processErrorCode(responseCode); fo#fg8zX%
return -2; //-2 represent access is error BxWPC#5
} HU8900k+
n,V[eW#m'L
c"n\cNP<
String sHeader; t~EPn.
]7F=u!/`<C
r4XK{KHn
for(int i=1;;i++) %Ycy{`
{ qn<|-hA*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R'bTN|Cq
//Utility.log(in.readLine()); +\c5]`
sHeader=httpConnection.getHeaderFieldKey(i); k}kQI~S9
if(sHeader!=null) +mmSfuO&\
{ 3G)#5Lf<
if(sHeader.equals("Content-Length")) 7uS~MW
{ 0w\zLU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l|~A#kq
break; vMi;+6'n>
} Jr ,;>
} D3Ig>gKo?m
else "$Z= %.3Q
break; J6s`'gFns
} qo90t{|c
} Ustv{:7v
catch(IOException e){e.printStackTrace ();} nQX:T;WL@
catch(Exception e){e.printStackTrace ();} uD$u2
hk(ZM#Bh
<EB+1GFuI
Utility.log(nFileLength); [#<-ZC#T*
@fZ,.2ar
I {S;L
return nFileLength; ( iBl
} M=.n7RY-
<CYd+! (
j^j1
//保存下载信息（文件指针位置） \:# L)
private void write_nPos() qPX~@^`9
{ fo*2:?K&
try{ H1pO!>M
output = new DataOutputStream(new FileOutputStream(tmpFile)); /yDz/>ID\
output.writeInt(nStartPos.length); cz#rb*b
for(int i=0;i<nStartPos.length;i++) 5,Jp[bw{H{
{ c)TPM/>(p
// output.writeLong(nPos); *v jmy/3
output.writeLong(fileSplitterFetch.nStartPos); h:b)Wr
output.writeLong(fileSplitterFetch.nEndPos); N ,'GN[s
} B4c]}r+
output.close(); -LoZs ru
} 8`q:Gz=M\
catch(IOException e){e.printStackTrace ();} lk^Ol&6
catch(Exception e){e.printStackTrace ();} ~:rl=o}
} 0U(@=7V
1b`1{%
~drS} V
//读取保存的下载信息（文件指针位置） zH?!
private void read_nPos() jH5 k
{ l[mWf
try{ ~NrG` D}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EnKR%Ctw
int nCount = input.readInt(); 'NXN& {
nStartPos = new long[nCount]; ?/wm(uL
nEndPos = new long[nCount]; [64:4/<}
for(int i=0;i<nStartPos.length;i++) Sxt"B
{ 7{e 4c
nStartPos = input.readLong(); fIx+ILs
nEndPos = input.readLong(); P%V'4pc
} k_L7 kvpt
input.close(); fa jGZyd0:
} >a!/QMh
catch(IOException e){e.printStackTrace ();} q~b&
catch(Exception e){e.printStackTrace ();} ^b4 9
} )Ys x}vSZ
vjbASFF0=
/wQy17g
private void processErrorCode(int nErrorCode) ,uSMQS-O'4
{ 9Z@hPX3.
System.err.println("Error Code : " + nErrorCode); GvtG(u~
} O40?{v'
lK?uXr7^
.9/hHCp
//停止文件下载 2RVN\?s:
public void siteStop() 7X`g,b!
{ 0#7>o^2
bStop = true; n*R])=F@c
for(int i=0;i<nStartPos.length;i++) g+8OekzB5
fileSplitterFetch.splitterStop(); "(3[+W{|
Q,,e+exbb5
i^/T
} j2t7'bO_
} e@L=LW>
//负责部分文件的抓取 @+&LYy72
**FileSplitterFetch.java x77*c._3v
*/ !{+,B5 Hc
package NetFox; t>L2
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JinUV6cr
import java.io.*; 70yFaW
import java.net.*; fF!Yp iI"
h/QXPdV
!4ocZmj\
public class FileSplitterFetch extends Thread { _>o:R$ %}
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+r�
String sURL; //File URL =}<IfNA
long nStartPos; //File Snippet Start Position 3<e=g)F
long nEndPos; //File Snippet End Position Yj<a" Gr4[
int nThreadID; //Thread's ID k90YV(
boolean bDownOver = false; //Downing is over bt@< ut\
boolean bStop = false; //Stop identical vOH4#
FileAccessI fileAccessI = null; //File Access interface XnH05LQ
3p$?,0ELH
i7CX65&b
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0.Q Ujw
{ %HhBt5w
this.sURL = sURL; ,5P0S0*{
this.nStartPos = nStart; +N]J5Ve-`t
this.nEndPos = nEnd; +WZX.D
nThreadID = id; k`cfG\;r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^L,K& Jd
} =bAx,,D#
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+X\FBvP&
public void run() dUD[e,?
{ vJLK,[
while(nStartPos < nEndPos && !bStop) s2a{>II6
{ {Ea b j
xf'V{9*
5p,RI&nlN
try{ W Tcw4
URL url = new URL(sURL); ;_XFo&@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K,tQ!kk
httpConnection.setRequestProperty("User-Agent","NetFox"); PioZIb/{
String sProperty = "bytes="+nStartPos+"-"; ]HbY
httpConnection.setRequestProperty("RANGE",sProperty); Ml`:UrU
Utility.log(sProperty); xW+6qtG`
mwO6g~@`
^23~ZHu
InputStream input = httpConnection.getInputStream(); 1wii8B6
//logResponseHead(httpConnection); mupT<_Y
ynp8rf
YByLoM*
byte[] b = new byte[1024]; }czrj%6
int nRead; W PC]%:L"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .zf~.R;>
{ gZVc 5u<
nStartPos += fileAccessI.write(b,0,nRead); &L3M]
//if(nThreadID == 1) "6A ` q\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {aZ0;
} #j;^\rSv-
IM*y|UHt
eB2a-,
Utility.log("Thread " + nThreadID + " is over!"); %q"%AauJR
bDownOver = true; D2#ZpFp"h
//nPos = fileAccessI.write (b,0,nRead); V(}:=eK
} oE6tauQn
catch(Exception e){e.printStackTrace ();} zxEL+P
} 7o\@>rNWP
} y4yhF8E>;U
^"E^zHM(
UB@Rs|)
//打印回应的头信息 ip\sXVR
public void logResponseHead(HttpURLConnection con) z>xmRs
{ rDtY[
for(int i=1;;i++) K&u_R
{ cUk7i`M;6
String header=con.getHeaderFieldKey(i); `Uq#W+r,
if(header!=null) vN}#Kc\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O}gV`q;
Utility.log(header+" : "+con.getHeaderField(header)); #x@$lc=k3
else eNh39er
break; ^+ml5m
} WH%g(6w1j
} cs48*+m
_r#Z}HK
qyb?49I
public void splitterStop() '(6z. toQ
{ %64)(z
bStop = true; `K"L /I9
} v4<nI;Ux
\Dm";Ay>
@ 6\I~s(
} Q)#B0NA;T
SZ7:u895E
ME$[=?7XX
/* Xc++b|k
**FileAccess.java Lpkyoh v
*//文件访问(定位，写) `b&%Hm
package NetFox; wKh4|Ka
import java.io.*; hwuiu*
]Ee?6]bN
y`iBFC;_
public class FileAccessI implements Serializable{ q~Hn-5H4Q
gE'sOT9v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8qoMo7-f
RandomAccessFile oSavedFile; Gf6p'(\zun
long nPos; E*&vy
Ha#=(9.
Ng&%o
public FileAccessI() throws IOException -12UN(&&Z
{ ,i NXK
this("",0); @)F)S7
} eSn+B;
Vsr.=Nd=
1NFsb-<u
public FileAccessI(String sName,long nPos) throws IOException J6"9v;V
{ -]Bq|qTH[(
oSavedFile = new RandomAccessFile(sName,"rw"); >tS'Q`R
this.nPos = nPos; *][`@@->
oSavedFile.seek(nPos); E)&I@m
} iO{hA
'ycJMYP8
Ep_HcX`
public synchronized int write(byte[] b,int nStart,int nLen) OG~gFZr)6
{ p>,|50|
int n = -1; YpHg&|Fr
try{ @)+AaC#-
oSavedFile.write(b,nStart,nLen); gk4;>}
n = nLen; Z3e| UAif
} /V8#[9K
catch(IOException e) &,vcJ{.
{ J-:.FKf\5l
e.printStackTrace (); T wB}l
} OF>mF~
>h1}~jW+
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return n; 1#g2A0U,
} jwe*(k]z
lgAoJ[
g9pZ\$J&
} h f)?1z4
mM~qBrwL
$p8xEcQdU#
/* T~?Ff|qFC
**SiteInfoBean.java X #dmo/L8
*/ :k]1Lm||
package NetFox; h^45,E C
tIi&;tw]
BR_1MG'{)$
public class SiteInfoBean { Z#jZRNU%ox
pQ">UL*
;V_e>TyG
private String sSiteURL; //Site's URL GAzU?a{S
private String sFilePath; //Saved File's Path H'5)UX@LP
private String sFileName; //Saved File's Name eIF5ZPSZi
private int nSplitter; //Count of Splited Downloading File ?,Xw[pR
je-!4r,
y1DL,%j
public SiteInfoBean() B IEO,W|
{//nSplitter的缺省值为5 HWAdhDZ
//default value of nSplitter is 5 m@j?za9s
this("","","",5); M^Yh|%M
} ja'T+!k
,,.QfUj/&
6- YU[HF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZoqZap6e
{ P[-E@0h)-t
sSiteURL= sURL; (Rh,,
sFilePath = sPath; 2"Q|+-Io
sFileName = sName; /N+dQe
this.nSplitter = nSpiltter; @7c?xQVd$
TqQB@-!
/HEw-M9z
} j;Gtu
7WqH&vU|
g =hg%gRy"
public String getSSiteURL() Paq4
{ ~_)^X
return sSiteURL; @;4zrzQi7
} G>=*yqo
octL"t8w
2s8a $3
public void setSSiteURL(String value) bj^5yX;2
{ ?81c 4w
sSiteURL = value; @{e}4s?7od
} ]q[D>6_
i"FtcP^
zk+9'r`-D
public String getSFilePath() P;no?
{ 2;b\9R^>A
return sFilePath; 1~FOgk1;
} rHI{aO7
I,DS@SK
QL/(72K
public void setSFilePath(String value) rXq.DvQ
{ c#]4awHU
sFilePath = value; ?R 'r4P,
} @4C% +-
qkqIV^*R
Y-z(zS^1
public String getSFileName() \l0[rcEf
{ =%O6:YM
return sFileName; fbvL7* (
} ~=LE0.3[
hE/cd1iJ$
)q4[zv9
public void setSFileName(String value) B-Hrex]
{ e>OoyDZ@R
sFileName = value; UDFDJm$
} Z\rwO>3
4"ZP 'I;
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public int getNSplitter() G!##X: 6'
{ C.P*#_R
return nSplitter; MjRHA^b
} $HzBD.CF|x
=XQ%t @z0
RP|`HkP-2
public void setNSplitter(int nCount) DCa^ u'f
{ -i|}m++
nSplitter = nCount; Gz0]}]A
} y.k~Y0
} 8Fh)eha9f
U/M>?G~
q?:dCFw$x5
/* &-w Cvp7
**Utility.java ejd(R+
*/ /nsX]V6i
package NetFox; pki%vRY
r5/0u(\LB
T>Z<]s
public class Utility { 0mVNQxHI
qR{=pR
hfTY.
public Utility() ?^{Ah}x
{ Izc\V9+
%1L,Y
kD%( _K5
} i]4I [!
n@i HFBb
//线程睡眠 T-L||yE,h
public static void sleep(int nSecond) vr l-$ii
{ u=sp`%?
try{ l)\! .X
Thread.sleep(nSecond); Fm 2AEs\
} +sA2WK]
catch(Exception e) |df Pki{
{ xo&_bMO
e.printStackTrace (); mJnIwdW*
} BxmWIItz
} 3d]S!=4H"
`wVyb>T
//日志 `h\j99
public static void log(String sMsg) J@'wf8Ub
{ "S]TP$O D
System.err.println(sMsg); jr."I+
} G` A4|+W"
zw[m9N5\h
EVSX.'&f
public static void log(int sMsg) tk`v:t!6U
{ /~?*=}c^m
System.err.println(sMsg); GxxW&y
} %> eiAB_b
} 7}>EJ
ki!0^t:9
"^-a M
/* WT=;:j
**TestMethod.java ~!L}yw
*/ 4VSU8tK|N]
package NetFox; Sm|6 %3
AkV#J, 3LC
eMsd37J
public class TestMethod { u#.2w)!D
x;d6vBTUb
O>,e~#!
public TestMethod() t~XN}gMxw
{ ///xx/weblogic60b2_win.exe yf+)6D -9n
try{ oPM96 (
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T5h H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tsjrRMR
SiteFileFetch fileFetch = new SiteFileFetch(bean); cwg"c4V
fileFetch.start(); z:*|a+cy
} D,feF9
catch(Exception e){e.printStackTrace ();} ?tbrbkx
wHy!CP%
fZF@k5*\
} HZge!Yp<
SJ,v?=S!
} Kgy
public static void main(String[] args) 5b*C1HS@X
{ 8ib:FF(= u
new TestMethod(); a~w$#fo"`f
} L8B!u9%
} K|, .C[
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