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)); qD#-q vn
} !{SU G+.2
for(int i=0;i<nEndPos.length-1;i++) MT#9x>
{ N_r*Ig
nEndPos = nStartPos[i+1]; h3xX26l
} {R,rc!yF
nEndPos[nEndPos.length-1] = nFileLength; eeb8v:4
} H$ xSl1>E
} Af0E_
4aB`wA^x
Ye!=
//启动子线程 $YaL3n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p9_45u`u2
for(int i=0;i<nStartPos.length;i++) '7'cKp
{ Z/uRz]Hi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O,JthlAV4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1xq1te)
nStartPos,nEndPos,i); /IV:JVT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kC9A
fileSplitterFetch.start(); YQX>)'
} T:.J9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hY'"^?OP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (DKpJCx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OR"ni
nEndPos = " + nFileLength); :@b>,{*4zS
// fileSplitterFetch[nPos.length-1].start(); V|?
05pCgI}F>
L1C'V/g
//等待子线程结束 NK#Dq&W+&
//int count = 0; 3+ i(fg_
//是否结束while循环 4 <]QMA0
boolean breakWhile = false; "v*RY "5#
4N` MY8',
p6}jCGJ
while(!bStop) 4VU5}"<
{ 4?yc/F=kI
write_nPos(); <U,T*Ql1x
Utility.sleep(500); 6lWO8j^BN
breakWhile = true; )If[pw@j
'pm2C6AC
V">Uh@[J_
for(int i=0;i<nStartPos.length;i++) q}\\p
{ p Y>yJ)
if(!fileSplitterFetch.bDownOver) U5Ho? `<
{ =$`DBLX
breakWhile = false; / V{w<
break; < m9O0
} ^~`8 - TE
} am"/Anml|
if(breakWhile) p6HZ2Q:a
break; 10}Zoq|)n
)uX:f8
U.^)|IHW
//count++; @JEr/yy
//if(count>4) mML^kgy\N
// siteStop(); r 2
} 'g=yJ
/d{L]*v)]
Q^p@ 1I
System.err.println("文件下载结束！"); ~AE034_N
} "rKIXy
catch(Exception e){e.printStackTrace ();} &%*S
} h |lQTT
%cm5Z^B1"
Bw#ubQJ8}
//获得文件长度 M5x!84
public long getFileSize() SY$%!! @R
{ eh`V#%S=
int nFileLength = -1; H_AV3 ;
try{ #/tdZ0
URL url = new URL(siteInfoBean.getSSiteURL()); <7jb4n<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?\O+#U%W
httpConnection.setRequestProperty("User-Agent","NetFox"); n7MS{`
v =?V{"wk!
W?l .QQk
int responseCode=httpConnection.getResponseCode(); )-QNWN H
if(responseCode>=400) ~lF lv+,%
{ }agl:~C
processErrorCode(responseCode); Q./lX:
return -2; //-2 represent access is error Hwc{%.%ae
} hL3,/^;E,
n47=eKd70
DdQf%W8u
String sHeader; y(]|jRo
:te xl
z\E"={P&
for(int i=1;;i++) t!T}Pg(Bo
{ >=`c [=:Z_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8x9kF]=
//Utility.log(in.readLine()); &Bp\kv
sHeader=httpConnection.getHeaderFieldKey(i); p;7 4+q
if(sHeader!=null) (k5DbP[
{ y[zA[H:
if(sHeader.equals("Content-Length")) -oZac
{ Fm;)7.% >
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cV{ZDq
break; qbEj\ b[
} ft'iv
} AslH V@K
else x7@WWFF>
break; Uo@NK
} '<0q"juXE
} >Y/[zfI2
catch(IOException e){e.printStackTrace ();} uTU4Fn\$L
catch(Exception e){e.printStackTrace ();} l'W+^
-/-6Td1JY>
zkp Apj].
Utility.log(nFileLength); :xw3b)KS
~^^ey17
?:?4rIZ<
return nFileLength; qp W#!Vbx
} @:7gHRJ!
bJ|?5
z/YMl3$l~
//保存下载信息（文件指针位置） '!-?
private void write_nPos() tqQ0lv^J
{ O$Vm#|$sq
try{ &Bn; Vi
output = new DataOutputStream(new FileOutputStream(tmpFile)); {}pqxouE
output.writeInt(nStartPos.length); q~J oGTv
for(int i=0;i<nStartPos.length;i++) R1.sq(z`
{ -m160k3
// output.writeLong(nPos); X[Ek'=}
output.writeLong(fileSplitterFetch.nStartPos); ~RXpz-Ye
output.writeLong(fileSplitterFetch.nEndPos); Ys$YI{
} O|Ic[XfLx
output.close(); T'M66kg
} y<`?@(0$
catch(IOException e){e.printStackTrace ();} #tZf>zrs
catch(Exception e){e.printStackTrace ();} nuQ6X5>.=
} mY`]33??v
R*@[Pg*
%%~}Lw
//读取保存的下载信息（文件指针位置） q{GSsDo-:V
private void read_nPos() >C3NtGvy
{ DvX3/z#T
try{ U+;>S$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }{8Fo4/
int nCount = input.readInt(); +oy&OKCa
nStartPos = new long[nCount]; ch>Vv"G>
nEndPos = new long[nCount]; hoR=%pC*
for(int i=0;i<nStartPos.length;i++) h1XMx'}B
{ @vQa\|j
nStartPos = input.readLong(); `xUG|
nEndPos = input.readLong(); _IL2-c8
} R|1xXDLm*E
input.close(); y-#
} qon{ g
catch(IOException e){e.printStackTrace ();} i7nL_N
catch(Exception e){e.printStackTrace ();} h.V]fS
} f>r3$WKj
'e]HP-Y<
\V^*44+ <!
private void processErrorCode(int nErrorCode) _(6`{PWY
{ 7':f_]
System.err.println("Error Code : " + nErrorCode); rKzlK 'U
} U,<]J*b(@4
0)AM-/"
nlzW.OLM
//停止文件下载 1n'$Ji7
public void siteStop() vUYJf99B
{ ;cI#S%uvpn
bStop = true; .Z=Ce!
for(int i=0;i<nStartPos.length;i++) yW\XNX
fileSplitterFetch.splitterStop(); b,sGq
hOPe^e"
lc[XFc
} jJ aV
} ]U,CKJF%/
//负责部分文件的抓取 '@TI48 J+
**FileSplitterFetch.java Hz?!BV0
*/ c^=R8y-N
package NetFox; 'y9*uT~
YwL`>?
d/{Q t
import java.io.*; c>ad0xce6
import java.net.*; <%z@
J&eAL3"GF
q2e]3{l3
public class FileSplitterFetch extends Thread { 4'SaEsA~
A&?}w_|9
H9RGU~q4s[
String sURL; //File URL AnNPTi
long nStartPos; //File Snippet Start Position ^m*3&x8
long nEndPos; //File Snippet End Position DVI7]+=nV
int nThreadID; //Thread's ID -(*nSD9
boolean bDownOver = false; //Downing is over BhKO_wQ?:J
boolean bStop = false; //Stop identical H]s4% 9T
FileAccessI fileAccessI = null; //File Access interface uBmxh%]C~
&hayR_F9
U98_M)-%&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |;P^clS3
{ p8=|5.
this.sURL = sURL; 9x=3W?K:,
this.nStartPos = nStart; -kl;!:'.3
this.nEndPos = nEnd; :NuR>~
nThreadID = id; 2"@Ft()]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OX+hZ<y
} *g1L$FBG
}W$8M>l
gN?0m4[$i
public void run() cC%j!8!
{ "u;YI=+
while(nStartPos < nEndPos && !bStop) -#aZF2z
{ LeSHRoD
:uo[&&c
Z:@6Lv?CN
try{ xuUx4,Z
URL url = new URL(sURL); ~:[!Uyp0b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .+yW%~0
httpConnection.setRequestProperty("User-Agent","NetFox"); =_ y\Y@J
String sProperty = "bytes="+nStartPos+"-"; !\;:36B#6
httpConnection.setRequestProperty("RANGE",sProperty); P16YS8$
Utility.log(sProperty); |SQ|qbe=
R"+wih
B3mS]
InputStream input = httpConnection.getInputStream(); b`CWp;6Y
//logResponseHead(httpConnection); tPU-1by$
+`.,| |Mq
:CaTP%GW
byte[] b = new byte[1024]; ;W{b $k@g
int nRead; 5ZK&fKeCF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Mvb':/M
{ 3qi_]*dD
nStartPos += fileAccessI.write(b,0,nRead); ^ve14mbF#.
//if(nThreadID == 1) Au.:OeJm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5G(E&>~
} {)@D`{$
{%b }Z2
LA4<#KP
Utility.log("Thread " + nThreadID + " is over!"); lY'N4x7n
bDownOver = true; {38\vX,I(w
//nPos = fileAccessI.write (b,0,nRead); WUEHB
} cp6WMHLj
catch(Exception e){e.printStackTrace ();} s-rfS7;
} ? \m3~6y
} uzBz}<M=
3yV'XxC
p[v#EyoC
//打印回应的头信息 9(,@aZ
public void logResponseHead(HttpURLConnection con) \+nGOvM
{ 3`F) AWzdr
for(int i=1;;i++) =Z,5$6%)
{ M#,Q ^rH#
String header=con.getHeaderFieldKey(i); j6g@tx^)'
if(header!=null) 8=;k"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'bu)M1OLi
Utility.log(header+" : "+con.getHeaderField(header)); >t <pFh
else OP! R[27>
break; #E$X,[ZFo
} }Hcx=}j
} ^6;V}2>v}
UBZ9A
>#(n"RCHf
public void splitterStop() !HK^AwNY
{ +?m0Q;%b
bStop = true; 6bO~/mpWT~
} 1||+6bRP
SJ?)%[(T
Bh]!WMAw.
} jqnCA<G~B-
@f1*eo5f
.Zmp,
/* Dg>^A
**FileAccess.java TNwKda+
*//文件访问(定位，写) V416g |lBO
package NetFox; [xZU!=
import java.io.*; G"dS+,Q
J CGC
;_?MX/w|&
public class FileAccessI implements Serializable{ , YW|n:X
ZC0-wr\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1zxq^BI
RandomAccessFile oSavedFile; c64v,Hj9
long nPos; 0?DC00O
(bp9Pjw
mpw~hW0-
public FileAccessI() throws IOException aA'TD:&p1
{ <|B1wa:|
this("",0); BJ}D%nm}
} b~m2tC=AW
YB(Gk;]
U7@AC}.+
public FileAccessI(String sName,long nPos) throws IOException Me5{_n
{ 5z}w}zdg
oSavedFile = new RandomAccessFile(sName,"rw"); <Zb/
this.nPos = nPos; )cJ#-M2
oSavedFile.seek(nPos); G3i !PwW
} `)iY}Iu
yay<GP?
8IQtz2
public synchronized int write(byte[] b,int nStart,int nLen) |SZo' 6
{ g=L]S-e
int n = -1; /phX'xp
try{ - YqYcer
oSavedFile.write(b,nStart,nLen); op2Of<{h
n = nLen; df}r% i
} 4R^mI
catch(IOException e) /6uT6G+(z}
{ >SF Uy\3
e.printStackTrace (); Bq\F?zk<
} z4%uN|V
t_z>Cl^u
%M F;`;1
return n; K7knK
} fEf_F r
$``1PJoi
!LMN[3M_
} Dr&('RZ4
1@48BN8cm'
>eQr<-8
/* B(a-k?
**SiteInfoBean.java S_MyoXV
*/ Pt:e!qX)
package NetFox; qU2~fNY
vy2Q g
=uk0@hy9b
public class SiteInfoBean { Ei}/iBG@
@+vXMJ$
U@ ?LP
private String sSiteURL; //Site's URL 6fH@wQ"wN
private String sFilePath; //Saved File's Path $E<Esf$
private String sFileName; //Saved File's Name #4MBoN(3
private int nSplitter; //Count of Splited Downloading File 3`d}~v{
?_x q-
s^0/"j|7
public SiteInfoBean() 4'j sDcs
{//nSplitter的缺省值为5 Ac2(O6
//default value of nSplitter is 5 Q?ahr~qo
this("","","",5); FMNm,O]
} v 8T$ &-HJ
S=R7`a<.5
D0k 8^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZUz ^!d
{ m }a|FS
sSiteURL= sURL; UDhG :
sFilePath = sPath; >_rha~
sFileName = sName; S(S#
this.nSplitter = nSpiltter; yKYUsp
'1,,)U#6E
?88[|;b3
} ~$'\L
Hsih[f
8^Hn"v
public String getSSiteURL() kKD`rfyG\
{ ;^*Unyt[4]
return sSiteURL; h\plQ[T
} FX9F"42@
u` oq(?|
-.g|l\
public void setSSiteURL(String value) |mdi]TL
{ D9`0Dr}/2
sSiteURL = value; ;Yi4Xva@
} )jq?lw'&
V"p!Bf
1;Pv0&[q/
public String getSFilePath() >zDF2Y[
{ h;=6VgXZ
return sFilePath; : ^ 8
} e[sK@jX6
*x)Ozfe
'9c2Q/
public void setSFilePath(String value) jTLSdul+
{ +C1QY'>I
sFilePath = value; SIbDj[s
} AuR$g7z
\~LQ%OM
8q1wHZ
public String getSFileName() rr#K"SP
{ mxb06u_
return sFileName; c/_+o;Bc
} Ou{v/'9z,
##Z_QB(;
b;)~wU=
public void setSFileName(String value) {.yStB.T
{ ]xguBh]
sFileName = value; `R"I;qV
} iCHt1VV]
FQ>`{%>
Q}S_%I}u:
public int getNSplitter() -hkQ2[Ew#
{ wvrrMGU)a
return nSplitter; ' B
} ~rjTF!
6sa"O89
wH~kTU2br
public void setNSplitter(int nCount) OgF+OS
{ >5Wlc$bc
nSplitter = nCount; &Q}*+Y]G
} ;Ag 3c+
} q5>v'ZSo
z&V+#Ws/
J)mhu}
/* 5=e@d:Sz
**Utility.java y>*xVK{D
*/ BL 3gKx.'
package NetFox; ",{ibh)g$`
F#|:`$t
)"+(butI&
public class Utility { 1Z{ZV.!
3=W!4
9o>8o
public Utility() Z'H5,)j0R
{ &i!vd/*WlD
pIbdN/z
wO2_DyMm@
} nYbhy}y
k1VT /u
//线程睡眠 +nQw?'9Z
public static void sleep(int nSecond) :{(w3<i
{ r!,}Z=cGe
try{ xV%6k{_:G
Thread.sleep(nSecond); WoxwEi1~0
} oA1a/[#
catch(Exception e) c^`]`xiX
{ wCk~CkC?
e.printStackTrace (); ?'"X"@r5
} HNL42\Kz!
} ]:34kE}e5
LL$_zK{
//日志 Ged[#Q
public static void log(String sMsg) lDmtQk-SN
{ fu$R7
System.err.println(sMsg); M@W[Bz
} _w*}\~`=^
H~ u[3LQz
5JhdVnT_
public static void log(int sMsg) Zf5`XslA.
{ KR"M/#
System.err.println(sMsg); ITy/eZ"&:
} JMdPwI
} $wYFEz
P9T5L<5
n&A'C\
/* -Z-IF#%
**TestMethod.java upvS|KUil
*/ *%vwM7
package NetFox; {647|j;e
Cye$H9 2
7Ol}EPf#
public class TestMethod { yPw'] "
:iR \%
Ej7 /X ~
public TestMethod() hm<}p&!J
{ ///xx/weblogic60b2_win.exe TPhTaKCio
try{ >MJg ,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8>/Q1(q0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mZIoaF>t
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~:km]?lz0
fileFetch.start(); a?YCn!
} l^J75$7
catch(Exception e){e.printStackTrace ();} w:'dhr':
m*X[ Jtr
NA,CZ
} m`6Yc:@E
'Pvm8t
4em;+ >D6
public static void main(String[] args) c"!lwm3b
{ Vx_rc%'
new TestMethod(); B^D(5
} ;IK[Y{W/
} rw)kAe31
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