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)); !Baq4V?KN
} ysQ8==`38i
for(int i=0;i<nEndPos.length-1;i++) x2z%J,z@4
{ >=ng?
nEndPos = nStartPos[i+1]; g/x\#W
} G 4C 7
nEndPos[nEndPos.length-1] = nFileLength; i)+2?<]
} +FYhDB~m
} &;oWmmvz{
[X=Ot#?u ~
{1]Of'x'
//启动子线程 ZTP&*+d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8(0q,7)y
for(int i=0;i<nStartPos.length;i++) G1:2MPH
{ Qrt> vOUE7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wvNddu>@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ceGo:Aa<)
nStartPos,nEndPos,i); JS!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LxxFosi8
fileSplitterFetch.start(); Fd@:*ER
} Ov9kD0S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D[R<H((
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >-YWq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,a?$F1Z-
nEndPos = " + nFileLength); "e~"-B7(\Y
// fileSplitterFetch[nPos.length-1].start(); oj~0zJI
Y7 `i~K;
9oJ=:E~CP
//等待子线程结束 j%OnLTZ
//int count = 0; "6fTZ<
//是否结束while循环 `)s>},8W!
boolean breakWhile = false; 7=x]p
z'ZGN{L
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while(!bStop) =o+))R4
{ 6z80Y*|eJ
write_nPos(); mu =H&JC
Utility.sleep(500); fF} NPl
breakWhile = true; aqAWaO
8k`rj;
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for(int i=0;i<nStartPos.length;i++) @}@J$ g
{ I!sB$=n
if(!fileSplitterFetch.bDownOver) -g]g
{ Um9]X@z
breakWhile = false; O8%Y .SK
break; b_T?jCyW
} naoH685R4
} Qs.g%
if(breakWhile) -l`1j6
break; f*^)0Po
, *A',
*eo<5YUHt
//count++; wIT}>8o
//if(count>4) *PJg~F%
// siteStop(); 79 ZBVe(}
} -O-qEQd
xl~%hwBd
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System.err.println("文件下载结束！"); PME ?{%&
} 0cm+:
catch(Exception e){e.printStackTrace ();} \#; -C<[b
} (S[" ak
jTJ]: EN
Z;#Ei.7p|
//获得文件长度 .<C}/Cl
public long getFileSize() :LwNOuavN
{ h[0,/`qb{
int nFileLength = -1; :5`BhFAd
try{ ~rX2oLw{&
URL url = new URL(siteInfoBean.getSSiteURL()); -Vi"hSsUP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @i[z4)"S
httpConnection.setRequestProperty("User-Agent","NetFox"); `9
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6n.W5 1g(s
int responseCode=httpConnection.getResponseCode(); $MEKt}S
if(responseCode>=400) t3)nG8> )
{ j&.MT@
processErrorCode(responseCode); FaNH+LPe
return -2; //-2 represent access is error )TBG-<wt
} \e/'d~F
9j[%Y?
/v1Rn*VF!
String sHeader; 6NV- &0 _
9 1r"-%(r
^p0BeSRiy;
for(int i=1;;i++) FasA f(3
{ {yy^DlHb
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bS+by'Ea1W
//Utility.log(in.readLine()); Dm1;mRS+
sHeader=httpConnection.getHeaderFieldKey(i); y+XB
if(sHeader!=null) n(gw%w+\7
{ 0vs9# <&V
if(sHeader.equals("Content-Length")) q=5#t~?
{ +FWkhmTv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Gv!* Qk4
break; ~$N%UQn?b#
} ~5HI9A4^
} 0.+"K}
else uOqWMRsoi
break; 1CiK&fQ'
} *FkG32k
} aD~3C/?aW
catch(IOException e){e.printStackTrace ();} m>gok0{pm
catch(Exception e){e.printStackTrace ();} c8sY#I
:o}Ju}t
a(X?N.w
Utility.log(nFileLength); p AzPi
;2vHdN
`um#}ify#
return nFileLength; LX e{
} )jK"\'cK
38dXfl
fmvX;0O
//保存下载信息（文件指针位置） ? {Lp
private void write_nPos() &Z_W*D
{ V@Z8t8
try{ +'H_sMmi{
output = new DataOutputStream(new FileOutputStream(tmpFile)); qJj;3{X2
output.writeInt(nStartPos.length); t]Xdzy
for(int i=0;i<nStartPos.length;i++) wwS{V
{ ;/W;M> ^
// output.writeLong(nPos); (63_
output.writeLong(fileSplitterFetch.nStartPos); FLO#!G
output.writeLong(fileSplitterFetch.nEndPos); )k0P' zGb
} *f:^6h
output.close(); bmotR8d
} M$z.S0"
catch(IOException e){e.printStackTrace ();} &j,rq?eh$
catch(Exception e){e.printStackTrace ();} F7`3,SzHp
} #;Y JR9VN
<JKRdIx&1
LXaT_3;
//读取保存的下载信息（文件指针位置） /a\6&Eb
private void read_nPos() yAoJ?<4^W
{ :luVsQ
try{ 8kw`=wSH>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [Z484dS`_
int nCount = input.readInt(); kScq#<Y&
nStartPos = new long[nCount]; =N`"%T@=
nEndPos = new long[nCount]; ]&1Kz 2/
for(int i=0;i<nStartPos.length;i++) 3~\mP\/4v
{ \iAkF`OC
nStartPos = input.readLong(); rLNo7i
nEndPos = input.readLong(); @<e+E"6
} ]5lp.#EB
input.close(); k+2~=#
} mvI[=e*
catch(IOException e){e.printStackTrace ();} w4 <FC$
catch(Exception e){e.printStackTrace ();} oBr/CW
} vBUx)l
2/qP:3)
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private void processErrorCode(int nErrorCode) S*6P=O*
{ 1Tf"<Dp
System.err.println("Error Code : " + nErrorCode); o~,dkV
} sB ]~=vUP
kC"<4U
<8p53*a
//停止文件下载 zCT Wi
public void siteStop() imAsE;:
{ ]lzt"[
bStop = true; [K;J#0V+&L
for(int i=0;i<nStartPos.length;i++) !CROc}
fileSplitterFetch.splitterStop(); 7=t4;8|j;
aEVBU
|jV>
} M"2Tuwz
} ~k?7XF I
//负责部分文件的抓取 n'{cU(
**FileSplitterFetch.java (Bd8@}\u_
*/ NH$a:>
package NetFox; SsfnBCVR
(7q!Z!2
_6&x$*O
import java.io.*; ozF>2`K }
import java.net.*; 2&O!<C j
&a%|L=FY
xSZgQF~
public class FileSplitterFetch extends Thread { ^ElUU?rX
WF<`CQg[
40N8?kQ}?
String sURL; //File URL 5BCXI8Ox9x
long nStartPos; //File Snippet Start Position hex:e2x
long nEndPos; //File Snippet End Position W[[3'JTF
int nThreadID; //Thread's ID D)XF@z;
boolean bDownOver = false; //Downing is over o ^L3Xiv
boolean bStop = false; //Stop identical tgH@|Kg
FileAccessI fileAccessI = null; //File Access interface y^tuybpZY<
Qx|m{1~-
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x):cirwkl
{ ";yCo0*
this.sURL = sURL; 7udMF3;>
this.nStartPos = nStart; Vm6G5QwM
this.nEndPos = nEnd; r7/y'Y]O
nThreadID = id; @dQIl#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I.TdYSB
} >4`("#
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public void run() 1GKd*z
{ [!p>Id
while(nStartPos < nEndPos && !bStop) #N_C|v/
{ cq+|fg~Yy
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&U ]L@]x
try{ xtYX}u
URL url = new URL(sURL); fEE[huG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DcA{E8Y
httpConnection.setRequestProperty("User-Agent","NetFox"); *,X;4?:,
String sProperty = "bytes="+nStartPos+"-"; jIwz G+)$P
httpConnection.setRequestProperty("RANGE",sProperty); 0P^RciC f
Utility.log(sProperty); (:Rj:8{
AJt*48H*G
:@{(^}N8u
InputStream input = httpConnection.getInputStream(); JsI`#
//logResponseHead(httpConnection); m07= _4
yKF"\^`@
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byte[] b = new byte[1024]; Cqy84!Z<
int nRead; ms8de>A|H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C-lv=FJEk/
{ ;75K:_
nStartPos += fileAccessI.write(b,0,nRead); Y~#m-y
//if(nThreadID == 1) 4Ei*\:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^WQ.' G5Q
} #qY`xH'>
^JZ]?iny
@ofivCc<%
Utility.log("Thread " + nThreadID + " is over!"); .6aC2A]es
bDownOver = true; n@ lf+
//nPos = fileAccessI.write (b,0,nRead); 3ha^NjE
} kx0(v1y3gT
catch(Exception e){e.printStackTrace ();} S[(Tpk2_
} Z8*E-y0
} Aon3G
P*Va<'{:{
Jt5\
//打印回应的头信息 <VI.A" Qk~
public void logResponseHead(HttpURLConnection con) pA7&
{ UIgs/
for(int i=1;;i++) "1|n]0BF
{ 2\80S[f
String header=con.getHeaderFieldKey(i); }A,9`
if(header!=null) F \6-s`(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); chk1tFV
Utility.log(header+" : "+con.getHeaderField(header)); _K["qm{X_
else -J*BY2LU3f
break; U Hh
} (~ro_WC/I
} ,Z*&QR
*Z'*^Y1le
4{4VC"fa
public void splitterStop() .anXsjD%W
{ DCr&%)Ll
bStop = true; E{x<P0 ;
} hB/4.K]8
pFb}5Q
__N< B5E
} -P#PyZEH&I
Ahl-EVIr<
"IQ' (^-P
/* >dO1)
**FileAccess.java R5OP=Q8
*//文件访问(定位，写) r Q)?Bhf
package NetFox; ZLm?8g6-
import java.io.*; nk=+6r6
*UBukn
,5}%_
public class FileAccessI implements Serializable{ ZNWo:N8;
&%eWCe++
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @GTkS!86
RandomAccessFile oSavedFile; +I~`Ob
long nPos; [ye!3h&]
pY@$N&+W
-u+@5K;^Y
public FileAccessI() throws IOException 2tPW1"M.n
{ N8*6sK.
this("",0); J:W|2U="
} v *'anw&Z
aia`mO]
HK}br!?
public FileAccessI(String sName,long nPos) throws IOException 2S%[YR>>
{ |q|?y`X4/
oSavedFile = new RandomAccessFile(sName,"rw"); h&5bMW
this.nPos = nPos; Hwb+@'o
oSavedFile.seek(nPos); 1M@OBfB8
} VZveNz@]r
zD}@QoB
X=C*PWa7
public synchronized int write(byte[] b,int nStart,int nLen) ?XCFRt,ol
{ \e)>]C}h
int n = -1; 9mA6nmp
try{ HrOq>CSR
oSavedFile.write(b,nStart,nLen); i28WgDG)5
n = nLen; A]<+Aq@{
} )ZZjuFQJ)
catch(IOException e) R:N4_4& C~
{ d `MTc
e.printStackTrace (); J!{"^^*
} GgT 5'e;N
+lYo5\1=
uX/K/4
return n; JRgrg&#
} I:|<};mm
h@kq>no
WZ@hP'Zc
} I1f4u6\*X
}xx"
ujin+;1
/* gm^j8B
**SiteInfoBean.java 6DkFIkS
*/ *sJT\J$D[
package NetFox; gWk?g^KJL
0Y>5&
pseN!7+or
public class SiteInfoBean { bm>N~DC
{UeS_O>(
lIhP\:;S&
private String sSiteURL; //Site's URL g49G7sk
private String sFilePath; //Saved File's Path I3I1<}>]Z
private String sFileName; //Saved File's Name Yamu"#
private int nSplitter; //Count of Splited Downloading File X&LaAqlSG
k2 _i;v
cePe0\\
public SiteInfoBean() 6 4,('+
{//nSplitter的缺省值为5 oMNt676
//default value of nSplitter is 5 !k3 eUBF
this("","","",5); cy-o@U"s8
} UWXl c
Ei HQ&u*
#zf,%IYF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I%|,KWM
{ nmo<t]
sSiteURL= sURL; `{KdmWhW
sFilePath = sPath; @> |3d
sFileName = sName; n[KLY!
this.nSplitter = nSpiltter; bmzY^ %a
| V:9 ][\
:kMF.9U:
} W(jOD,QMB
}/bxe0px
1agNwFd~
public String getSSiteURL() )5[OG7/g
{ c80Ffq
return sSiteURL; gf ?_tB0C
} ROhhd.
F$sDmk#
+^<s'
public void setSSiteURL(String value) H:#sf][&,L
{ !kxJ&VmeF
sSiteURL = value; P @Jo[J<
} %O|+`"
0SV<Pl^
eF"k"Ckt'
public String getSFilePath() 3<x1s2U
{ $2E&~W %
return sFilePath; 41v#|%\w
} 1j*E/L
y3 "+4e
a$=He
public void setSFilePath(String value) ^qY?x7mx1
{ eH_< <Xh!v
sFilePath = value; XfQK kol
} L`"j>),
gs"w 0[$
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public String getSFileName() _. &N@k
{ *Y':raP
return sFileName; gF>t+"+x
} m9=93W?
Pihpo
J#DN2y<
public void setSFileName(String value) )Drif\FF)
{ H?_wsh4J
sFileName = value; #|"M
} (zX75QSKV
t-i\gq^
gX|We}H
public int getNSplitter() NmA6L+
{ |{ @BH
return nSplitter; z*)kK
} N(l
eakQZ-Q
r3NdE~OAi
public void setNSplitter(int nCount) "x0/i?pqa
{ D0}r4eA
nSplitter = nCount; /o^/J~/3
} _+9o'<#u(
} >}E
G3o`\4p
}60/5HNr
/* $jOp:R&I^3
**Utility.java r+!29
*/ O+?vQ$z
package NetFox; Jr=XVQ(F
!C@+CZXLx
{G+iobQdd
public class Utility { 9S|a!9J
[]$L"?]0uk
u]OYu
public Utility() +~V)&6Vn
{ IuY4R0Go
&^7(?C'u
Qd/x{a8
} 4"pU\g
-%dBZW\u2
//线程睡眠 !;UoZ~
public static void sleep(int nSecond) w$Z%RF'p
{ "QvTn=
try{ N F,<^ u
Thread.sleep(nSecond); CiV^bYi
} ^ib =fLu
catch(Exception e) mqtYny'
{ &3OV|ly]
e.printStackTrace (); dJe 3DW :
} _SnD)k+TgJ
} :=*V i`
ZfXgVTJ`
//日志 &x\cEI)!
public static void log(String sMsg) 4t-l@zFWb
{ #5=W[+4eN
System.err.println(sMsg); CFUn1^?0
} [1mEdtqf*
V`8\)FFG
c#f@v45
public static void log(int sMsg) x!6<7s
{ vY7@1_"
System.err.println(sMsg); X}wo$t
} 4y.qtiIP>$
} &smZ;yb|'h
~e&O?X
A&A{Thz
/* ~9PZ/( '
**TestMethod.java pekNBq Wm
*/ ?AH B\S
package NetFox; l.P;85/+
IL1iTRH
-Jf}3$Ra
public class TestMethod { 1aZGt2;
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w"37sv
public TestMethod() H>Ucmd;ay
{ ///xx/weblogic60b2_win.exe dUUg}/
try{ ' &3,qT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ia (&$a8X
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ROXa/
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~uV(/?o%
fileFetch.start(); 1IlOU|4
} E3] 8(P%D-
catch(Exception e){e.printStackTrace ();} :5F(,Z_
l"7#(a
U~d%5?q
} >=:^N-a
_Ie:!q
sm;kg=
public static void main(String[] args) H@u5&
{ e,r7UtjoxR
new TestMethod(); s7sTY
} a`[9<AM1#
} h?H|)a<^9
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