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)); jzI,B
} d:hX3
for(int i=0;i<nEndPos.length-1;i++) )$O'L7In&
{ g{hbq[>X]
nEndPos = nStartPos[i+1]; &hWYw+yH\
} kcP&''
nEndPos[nEndPos.length-1] = nFileLength; Slp_o\s$@
} NRs%q}lX
} iP?lP= M
~-A"M_n ?
,!98VJmr
//启动子线程 xz}=C:s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h3p~\%^
for(int i=0;i<nStartPos.length;i++) A*W/Q<~I
{ :ZXaJ!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4@@gC&:Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &qm:36Y7Xg
nStartPos,nEndPos,i); F&OcI.OTXF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k[1w] l8
fileSplitterFetch.start(); %kk~qvW
} X-SR0x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _!o0bYD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Gx(%AB~9$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?1H>k<Jp
nEndPos = " + nFileLength); ro^T L
// fileSplitterFetch[nPos.length-1].start(); -B:O0;f
{InW%qSn_
k-$J #
//等待子线程结束 /$UWTq/C7
//int count = 0; lH>6;sE
//是否结束while循环 6/|"y
boolean breakWhile = false; T{Yk/Z/}?
`^DP<&{
D!bi>]Yd
while(!bStop) '>% c@C[
{ h6e,w$IL
write_nPos(); p5bM/{DP;K
Utility.sleep(500); V`LW~P;
breakWhile = true; V V Aw y6
SXmh@a"*\
OJ}aN>k
for(int i=0;i<nStartPos.length;i++) ^I!gteU;
{ L$}'6y/@
if(!fileSplitterFetch.bDownOver) w1t0X{
{ &-ZRS/_d>
breakWhile = false; Q8bn|#`
break; 2spK#0n.HV
} )h;zH,DA[3
} [.4D<}e
if(breakWhile) fq0[7Yb
break; Y1 6pT
3$kElq[
Ijs=4f
//count++; *q(HW
//if(count>4) $I90KQB\_
// siteStop(); |(R[5q
} #pX+~{
zuBfkW95+
.t{?doOT
System.err.println("文件下载结束！"); '8fh(`
} Q9 RCN<!
catch(Exception e){e.printStackTrace ();} 2pAshw1G
} "C [uz&
:,=Z)e
Re'Ek
//获得文件长度 8R.`*
public long getFileSize() O}"fhMk
{ OGU#%5"<
int nFileLength = -1; *wJ'Z4_5F
try{ O;<YLS^|6
URL url = new URL(siteInfoBean.getSSiteURL()); R)qK{wq(1E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =v/x&,Uj@6
httpConnection.setRequestProperty("User-Agent","NetFox"); tD}HL_
74*iF'f?c
.@]M'S^1
int responseCode=httpConnection.getResponseCode(); vghn+P8
if(responseCode>=400) IctLhYZ
{ Q@#Gm9m
processErrorCode(responseCode); &SK=ZOKg^
return -2; //-2 represent access is error \{`*`WQF
} `G.:G/b%H
*gXm&/2*
+l_$}UN
String sHeader; -<B{?D
eE;")t,
9 !qVYU42(
for(int i=1;;i++) dCM*4B<
{ _7w2E
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5Ai$1'*p
//Utility.log(in.readLine()); q CB9z
sHeader=httpConnection.getHeaderFieldKey(i); E.~~.2
if(sHeader!=null) %epK-q9[
{ W4(O2RU
if(sHeader.equals("Content-Length")) !#8=tO
{ Nm/Fc
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n;Etn!4M
break; Y^f12%
} H=k*;'
} r#[YBaCZJ
else yLlAK,5P0o
break; E={W^k!Vz:
} rfNt
} /1q] D8
catch(IOException e){e.printStackTrace ();} "A?_)=zZ
catch(Exception e){e.printStackTrace ();} q<cpU'-#
>h m<$3
*oX~z>aE
Utility.log(nFileLength); XL7jUi_4:L
;"/ "
L"6@3
return nFileLength; I"=XM
} \;A\ vQ[
=`]yq;(C7j
(8(z42
//保存下载信息（文件指针位置） [2,u:0"
private void write_nPos() RFu]vFff
{ V-w[\u
try{ o*u A+7n
output = new DataOutputStream(new FileOutputStream(tmpFile)); %R{clbbbn
output.writeInt(nStartPos.length); G#4cWn'
for(int i=0;i<nStartPos.length;i++) BE}qwP^
{ 9bT,=b;
// output.writeLong(nPos); :8aIj_qds
output.writeLong(fileSplitterFetch.nStartPos); rkl/5z??
output.writeLong(fileSplitterFetch.nEndPos); y|X\f!
} |JL47FR
output.close(); wWflZ"%
} 6X:-Z3
catch(IOException e){e.printStackTrace ();} O!uB|*
catch(Exception e){e.printStackTrace ();} dR_hPBn/@
} @]HV:7<q
k>Qr14F
kc8T@5+I0
//读取保存的下载信息（文件指针位置） <_H0Q_/(
private void read_nPos() !`='K +
{ bct&ge7YX
try{ )[)-.{q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0p$?-81BJ
int nCount = input.readInt(); ^ :Q |,oy
nStartPos = new long[nCount]; ap9eQsC
nEndPos = new long[nCount]; 4#=!VK8ZH
for(int i=0;i<nStartPos.length;i++) v.v3HB8p
{ # dxlU/*
nStartPos = input.readLong(); M)EUR0>8
nEndPos = input.readLong(); jt2m-*aP
} Ye!=
input.close(); $YaL3n
} lLtC9:
catch(IOException e){e.printStackTrace ();} EGGy0ly
catch(Exception e){e.printStackTrace ();} sS(^7GARa
} ?-\KVha
ZLKS4
L +.K}w
private void processErrorCode(int nErrorCode) +I\bs.84
{ AD?^.<
System.err.println("Error Code : " + nErrorCode); w6Tb<ja
} r?/>t1Z
.FHOOw1r=
>cMU<'&
//停止文件下载 V|?
public void siteStop() 05pCgI}F>
{ "TjR]jnV(
bStop = true; 9R;s;2$.
for(int i=0;i<nStartPos.length;i++) YBS]JCO
fileSplitterFetch.splitterStop(); S8,+6+_7
/e{Oqhf[n
N{p2@_fnB
} @1Zf&'/6
} [V jd)%
//负责部分文件的抓取 KI>7h.t
**FileSplitterFetch.java ;-]f4O8
*/ `(o1&
package NetFox; B4|%E$1+
U;V. +onv
H#Og0gEE}5
import java.io.*; zLh ~x
import java.net.*; eIqj7UY_
^*{xTB57
(J^ Tss
public class FileSplitterFetch extends Thread { acGmRP9g
b0t];Gc%b
:Dr& {3>
String sURL; //File URL Yaa M-o
long nStartPos; //File Snippet Start Position dNJK[1e6
long nEndPos; //File Snippet End Position i*U\~CZjT
int nThreadID; //Thread's ID +.lO8
boolean bDownOver = false; //Downing is over WVNQ}KY
boolean bStop = false; //Stop identical Aoo'i
FileAccessI fileAccessI = null; //File Access interface C,IN+@
n3|~X/I
{YGz=5^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s*8hN*A/,
{ /d{L]*v)]
this.sURL = sURL; QOF;j#H^
this.nStartPos = nStart; 'Vrev8D
this.nEndPos = nEnd; =AKW(v
nThreadID = id; BO9Z"|"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %cm5Z^B1"
} Bw#ubQJ8}
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l.34h
public void run() [{{?e6J
{ H_AV3 ;
while(nStartPos < nEndPos && !bStop) #/tdZ0
{ <7jb4n<
T*{zL
)Xh_q3=
try{ "w'YZO]>
URL url = new URL(sURL); `?D_=Gw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fN4pG*D
httpConnection.setRequestProperty("User-Agent","NetFox"); HJ'93,
String sProperty = "bytes="+nStartPos+"-"; n5JB'F)
httpConnection.setRequestProperty("RANGE",sProperty); qIqk@u
Utility.log(sProperty); ILO+=xU
FSQ&J|O
V?O%kd
InputStream input = httpConnection.getInputStream(); a:|4q
//logResponseHead(httpConnection); L$Leo6<3a
GY",AL8f
fhY[I0;}$
byte[] b = new byte[1024]; dI 5sqM:
int nRead; k,@J&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nM; G; T
{ &S3W/lQs
nStartPos += fileAccessI.write(b,0,nRead); *M|\B|A.
//if(nThreadID == 1) :HE]P)wz-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #pe{:f?
} #w*pWD^
8@fDn(]w
YT5>pM-%
Utility.log("Thread " + nThreadID + " is over!"); 38m%ifh)
bDownOver = true; PD}R7[".>
//nPos = fileAccessI.write (b,0,nRead); &CL|q+-
} v2n0[b0
catch(Exception e){e.printStackTrace ();} )a^Yor)o"
} p\{+l;`
} 3opLLf_g
8Wj=|Ow-q
sv;zvEn;-L
//打印回应的头信息 bNROXiX
public void logResponseHead(HttpURLConnection con) `oMeR]~
{ @"I#b99
for(int i=1;;i++) 2ZO'X9
{ <nvWC/LU
String header=con.getHeaderFieldKey(i); f^)uK+:.
if(header!=null) eCp|QSXE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nF'xV44"
Utility.log(header+" : "+con.getHeaderField(header)); ~& 5&s
else &Bn; Vi
break; A(n=kx
} &{ {DS
} IMGqJc,7
>'6GcnEb4.
5b#6 Y
public void splitterStop() j#e.rNG
{ {%_j~
bStop = true; M_1Tx
} gOyY#]g
@LKG\zYBu
y<`?@(0$
} AD@PNM
Tj=dL
{TncqA
/* &^IcL!t[
**FileAccess.java ^ 6.lb\
*//文件访问(定位，写) }[z<iij4
package NetFox; A$~xG(
import java.io.*; )E:,V~< 8
^QAiySR`0
;:Z=%R$wJ
public class FileAccessI implements Serializable{ bW9"0=j[{
lV<Tsk'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #jZ@l3
RandomAccessFile oSavedFile; `<J#l;y
long nPos; HRV*x!|I
/u)Rppu
v'@b.R,
public FileAccessI() throws IOException kwHqvO!G
{ N\q)LM !M
this("",0); i~)NQmH<
} h.V]fS
f>r3$WKj
VD24X
public FileAccessI(String sName,long nPos) throws IOException *AH^%!kVP
{ 7%9)C[6NSs
oSavedFile = new RandomAccessFile(sName,"rw"); "#twY|wW
this.nPos = nPos; |qlS6Aln
oSavedFile.seek(nPos); 85D^@{
} "#pzZ)Zh
HK0::6n{
1n'$Ji7
public synchronized int write(byte[] b,int nStart,int nLen) j u*fyt
{ H#L#2M%
int n = -1; S<nP80C
try{ EqnpMHF
oSavedFile.write(b,nStart,nLen); )C {h1 `
n = nLen; dk_,YU'z
} \Mb(6~nC
catch(IOException e) qO-C%p [5
{ hr$Sa
e.printStackTrace (); '@TI48 J+
} Hz?!BV0
/vjGjb=3U
f.oP
return n; $Z;BQJVH
} 2{ o0@
(*,8KLV_i
p9-0?(]
} Di*]ab
$!G`D=
bj@xqAGl
/* HG2GZ}~^1
**SiteInfoBean.java BeK2;[5C
*/ 2sKG(^=Z
package NetFox; \M5P+Wk'
=<{h^-j;a
EeCFII
public class SiteInfoBean { P##Z[$IJ3
W`$[j0
D?e"U_
private String sSiteURL; //Site's URL JO2xT#V
private String sFilePath; //Saved File's Path TPHYz>D]
private String sFileName; //Saved File's Name !!FR[NK
private int nSplitter; //Count of Splited Downloading File 9\v.qo.
~m=$VDWm
S'o ]=&
public SiteInfoBean() .Y1bY:=
{//nSplitter的缺省值为5 2FGx _Y
//default value of nSplitter is 5 $uCiXDKCq
this("","","",5); XaW4C-D&
} tBseqS3<
a/~29gW8E\
="\*h(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W;q+,Io
{ CtM'L
sSiteURL= sURL; w NH9WG
sFilePath = sPath; gN?0m4[$i
sFileName = sName; lEHwZ<je
this.nSplitter = nSpiltter; /xySwSmh3
[Tb\woU
3jF|Ic
} -#aZF2z
&]< 3~6n
O)uOUB
public String getSSiteURL() EJLQ&oH[
{ vU!8`x)
return sSiteURL; Z:@6Lv?CN
} _gW{gLYyJ
)lh8 k{
tMFsA`ng
public void setSSiteURL(String value) h4(JUio
{ *69c-`o
sSiteURL = value; XJSa]P^B1
} R}r~p?(M
/b#q*x-b
HzvlF0f
public String getSFilePath() d&jjWlHgEN
{ BwxnDeG)
return sFilePath; rjUBLY1(
} V^n0GJNo
JrDHRIkgm
QU/fT_ORw
public void setSFilePath(String value) Uk,g> LG
{ LkBZlh_
sFilePath = value; z(me@P!D~
} >)Gd:636+
+`.,| |Mq
F;u_7OM
public String getSFileName() x=]S.XI
{ -U-P}6^
return sFileName; IU#x[P!
} 5ZK&fKeCF
d~@q%-`lA
/r^[a,Q#x
public void setSFileName(String value) s+,&|;Q
{ m'x;,xfY&F
sFileName = value; b,@aqu
} %d;<2b0
tnb$sulc+
VFj(M j`}G
public int getNSplitter() /0lC KU!=
{ =eBmBn
return nSplitter; z/7$NxJH
} gnLn7?
>A}0Ho
LA4<#KP
public void setNSplitter(int nCount) ;`(R7X *3
{ [2 zt ^
nSplitter = nCount; 8IGt4UF&?
} _1|$P|$P.
} JA^v
7I}P*%(f
#BY`h~&T
/* ``|AgIg
**Utility.java 6/tI8H3E
*/ SfB8!V|;
package NetFox; m"d/b~q
uzBz}<M=
?j{C*|yHO
public class Utility { OBOwz4<
T_;]fPajjD
DlTR|(AL
public Utility() A:# k
{ DBsDkkB{
Z4hLdHo_
B4g8 ~f
} >t <pFh
(\,BxvhG=
//线程睡眠 #E$X,[ZFo
public static void sleep(int nSecond) }Hcx=}j
{ ^6;V}2>v}
try{ 3l4NC03I&
Thread.sleep(nSecond); @T:faJ5\'
} B_^]C9C|
catch(Exception e) bw4oLu?
{ #=,imsW)
e.printStackTrace (); SO{p;g
} nFM@@oA
} 2oVV'9;B
DN8}glVxV
//日志 ~i0R^qfr
public static void log(String sMsg) / T c=
{ #VGjCEeU
System.err.println(sMsg); b]Z@^<_E
} aFj.i8+
@;Opx."
?jO 5 9n
public static void log(int sMsg) <l,o&p,>|c
{ u0o'K9.r
System.err.println(sMsg); NwlU%{7W6
} xJwG=$o
} },@^0UH4c
Ykqyk')wm
bzZ>lyH
/* b-^p1{A0zW
**TestMethod.java kkCZNQ~I
*/ Y&.UIosWb
package NetFox; {b)~V3rsY
)2e#HBnH
Vb|#MNf)
public class TestMethod { ZC0-wr\
JXqr3Np1
c64v,Hj9
public TestMethod() ,'fxIO
{ ///xx/weblogic60b2_win.exe TQ@d~GR
try{ w#y0atsg'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]j<Bo4~Il
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ZWUP^V
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^jE8+h
fileFetch.start(); W"q@Qa`Bm
} *OjKcs
catch(Exception e){e.printStackTrace ();} An`3Ex[
IE2"rQT
Orn0Zpp<z
} ]T:;Vo
f9u^R=Ff[
hT g<*
public static void main(String[] args) `#P$ ]:
{ S>Yj@L
new TestMethod(); :[l\@>H1tX
} .Ajzr8P
} R`8@@}
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