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)); I\6^]pi,
} ZN`I4Ak
for(int i=0;i<nEndPos.length-1;i++) s.!gsCQme
{ A6F/w
nEndPos = nStartPos[i+1]; `9VRT`e
} i~*#z&4A+
nEndPos[nEndPos.length-1] = nFileLength; 4V5h1/JPm
} A@G%*\UZ
} *i7|~q/u
(Mt-2+"+
n\4sNoFI
//启动子线程 vQ DlS1L
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !o`h*G-x
for(int i=0;i<nStartPos.length;i++) vj<JjGP
{ wb-_CQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qnv)\M1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ca$K)=cDW
nStartPos,nEndPos,i); SfwNNX%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?xCWg.#l4V
fileSplitterFetch.start(); y$HV;%G{26
} 8<X; 8R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D3;#:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `CEHl &w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <825?W|
nEndPos = " + nFileLength); 'di(5
// fileSplitterFetch[nPos.length-1].start(); ;XGO@*V5T
w:[\G%yQ
e[L%M:e9U
//等待子线程结束 N/N~>7f
//int count = 0; [-JU(:Rh
//是否结束while循环 yK:b$S
boolean breakWhile = false; rW0-XLbL5H
.OSFLY#[?
%8g1h)F"S
while(!bStop) V82N8-l
{ </jTWc'}
write_nPos(); IkJ-*vI6
Utility.sleep(500); Ya-kMUW
breakWhile = true; @ M
8{4jlL;"`?
xr1,D5
for(int i=0;i<nStartPos.length;i++) Ex}hk!
{ P jh3=Dr
if(!fileSplitterFetch.bDownOver) 0ZJt
{ [$%O-_x
breakWhile = false; ^;a~_9 m-
break; #>dj!33
} zP|^) h5
} |tuh/e@dx
if(breakWhile) ^s?=$&8f![
break; xv>]e <":
MI\35~JAN
Q6rvTV'vv
//count++; `ehcj G1nY
//if(count>4) &'<e9
// siteStop(); D $3Mg
} j NkobJ1
.I nDyKt
'nSo0cyQ
System.err.println("文件下载结束！"); b,uudtlH
} I::|d,bR!
catch(Exception e){e.printStackTrace ();} ?]PE!7H
} 'Uu!K!
3 G_0DS
0Tq=nYZA
//获得文件长度 :B 9>
public long getFileSize() ?Es(pwJB
{ On-zbE
int nFileLength = -1; M2lvD&
try{ T1#r>3c\
URL url = new URL(siteInfoBean.getSSiteURL()); |Q?^Ba
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hU6oWm
httpConnection.setRequestProperty("User-Agent","NetFox"); chA7R'+LA
&$g{i:)Z
x7ZaI{
int responseCode=httpConnection.getResponseCode(); +FJ+,|i
if(responseCode>=400) w?:tce
{ (NC]S
processErrorCode(responseCode); IRyZ0$r:e\
return -2; //-2 represent access is error h5<eU;Rw+
} |wINb~trz
.C,D;T{
#pcgfVl
String sHeader; ?"$Rw32
6|n3e,&A2
0TWd.+
for(int i=1;;i++) QTC!vKM
{ oju,2kpH7#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -}(2}~{e(
//Utility.log(in.readLine()); <.".,Na(J0
sHeader=httpConnection.getHeaderFieldKey(i); JIPBJ
if(sHeader!=null) Z7XFG&@6
{ Q$(Fma4a
if(sHeader.equals("Content-Length")) pZz\o
{ {$g3R@f^~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L3=5tuQ[5
break; =;"=o5g_
} &-Ylj
} lg +>.^7k
else F3[,6%4v
break; LUdXAi"f
} wJj:hA}
} _&%FGcAS
catch(IOException e){e.printStackTrace ();} 6H=gura&
catch(Exception e){e.printStackTrace ();} S$ffTdRz
F3hG8YX
gxx#<=`
Utility.log(nFileLength); (x fN=Te,-
y @S_CB47
NfUt\ p*
return nFileLength; "}V_.I*+
} DD2K>1A1
V';l H2
H@1}_d
//保存下载信息（文件指针位置） K)U[xS;<
private void write_nPos() vA}_x7}n(
{ gB~^dv {
try{ 5vg="@O K
output = new DataOutputStream(new FileOutputStream(tmpFile)); bf|ePGW?
output.writeInt(nStartPos.length); A,BYi$
for(int i=0;i<nStartPos.length;i++) f}J(nz>Sh
{ FWA?mde
// output.writeLong(nPos); sQe GT)/|
output.writeLong(fileSplitterFetch.nStartPos); \ 'Va(}v
output.writeLong(fileSplitterFetch.nEndPos); 2,wwI<=E'
} vd)zvI
output.close(); z$WLx
} SnR2o3r-Of
catch(IOException e){e.printStackTrace ();} }opw_h+/F
catch(Exception e){e.printStackTrace ();} 4hODpIF
} 0Ni{UV? k
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_&/ {A|n
//读取保存的下载信息（文件指针位置） M(zZ8#
private void read_nPos() xEk8oc
{ S>r",S
try{ ~`C_B]3|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !nCq8~#
int nCount = input.readInt(); ?*%_:fB
nStartPos = new long[nCount]; !Av9?Q:
nEndPos = new long[nCount]; X.#)CB0c1Q
for(int i=0;i<nStartPos.length;i++) U2A 82;Z
{ H#DvCw
nStartPos = input.readLong(); c~?Zmdn:
nEndPos = input.readLong(); s<)lC;#e
} 0'fswa)
input.close(); kJp~'\b
} c#sHnpP
catch(IOException e){e.printStackTrace ();} &8z<~q
catch(Exception e){e.printStackTrace ();} dw3Hk$"h
} P=5+I+
~e 1l7H;
{VL@U$'oI
private void processErrorCode(int nErrorCode) 7P7OTN
{ 8.#{J&h
System.err.println("Error Code : " + nErrorCode); 0n}13u=}
} m&Mupl
G$+v |z
k=hWYe$iAz
//停止文件下载 DzQBWY] )
public void siteStop() +t+<?M B
{ \ph.c*c
bStop = true; 4 "HX1qP
for(int i=0;i<nStartPos.length;i++) K"H\gmV_g
fileSplitterFetch.splitterStop(); \A"o[A2v
9)ALJd,M
_!R$a-
} }OL"38P
} 3KkfQ{
//负责部分文件的抓取 KLg1(W(
**FileSplitterFetch.java rP3HR5
*/ UJ)pae
package NetFox; K>@yk9)vi
En?V\|,
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import java.io.*; ?Gki0^~J
import java.net.*; bf"'xn9
/x6p
\^c4v\s<o#
public class FileSplitterFetch extends Thread { D(#f`Fj;
q8v[u_(yD
*?rWS"B
String sURL; //File URL qN)y-N.LI(
long nStartPos; //File Snippet Start Position 3'0Pl8
long nEndPos; //File Snippet End Position pk/#RUfT+
int nThreadID; //Thread's ID Nr~$i%[
boolean bDownOver = false; //Downing is over vk& gR
boolean bStop = false; //Stop identical Ke\\B o,
FileAccessI fileAccessI = null; //File Access interface N+|NI?R?}
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lLx!_h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >='/%Ad
{ <'a~Y3B"o
this.sURL = sURL; U(#<D7}
this.nStartPos = nStart; I0Pw~Jj{
this.nEndPos = nEnd; :v&[!
nThreadID = id; b(H{i}{]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ps!MpdcL3
} 1-KNXGb'
tIsWPt]Y
iC gZ3M]
public void run() yB b%#GW
{ wVs?E
while(nStartPos < nEndPos && !bStop) >XD?zF)6
{ > ;,S||
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Bt+^H6cb
try{ U v2.Jo/Q
URL url = new URL(sURL); h0GoF A<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3o<d=@`r
httpConnection.setRequestProperty("User-Agent","NetFox"); 4T@:_G2b
String sProperty = "bytes="+nStartPos+"-"; N9e'jM>Oos
httpConnection.setRequestProperty("RANGE",sProperty); q2qi~}l
Utility.log(sProperty); g{8RPw]
DXFu9RE\{
{i5?R,a)
InputStream input = httpConnection.getInputStream(); oxwbq=a6yV
//logResponseHead(httpConnection); @T'^V0!-q:
1^~&"s U
"HMEoZ
byte[] b = new byte[1024]; *;7y5ZJ
int nRead; (m~>W"x/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b/SBQ"B%
{ 8:ubtB
nStartPos += fileAccessI.write(b,0,nRead); ewZ?+G+m
//if(nThreadID == 1) Kl1v^3\{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w_9^YO!!
} `KJ(.m
,6)N.
TBj2(Z
Utility.log("Thread " + nThreadID + " is over!"); DeO-@4+qKd
bDownOver = true; @=-(H<0
//nPos = fileAccessI.write (b,0,nRead); Y-VDi.]W
} W^(zP/
catch(Exception e){e.printStackTrace ();} pwFp<O"
} ^QK`z@B
} om3 %\
`MtzA^Xr
L\:|95Yq
//打印回应的头信息 rTPgHK]?l
public void logResponseHead(HttpURLConnection con) 3Cf9'C
{ &?<uR)tl
for(int i=1;;i++) LUOjaX
{ ]\E"oZ
String header=con.getHeaderFieldKey(i); y Zafq"o
if(header!=null) vygzL U^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "J VIkC
Utility.log(header+" : "+con.getHeaderField(header)); bLqy7S9x
else .<x6U*)\O
break; ~Y 6'sM|
} *ap,r&]#F
} -Q WvB
]\,?u /
x|H`%Z
public void splitterStop() 4TtC~#D:
{ Gh;\"Qx
bStop = true; qmS9*me {
} ,jU>V]YC
yD\q4G
Tz @<hE
} m`yvZ4K!
i7x&[b
~7m`p3W@
/* c%&,(NJ]K
**FileAccess.java ]'.qRTz'\t
*//文件访问(定位，写) YteIp'T
package NetFox; `3TR`,=
import java.io.*; {K^5q{u
'L/)9.29
26V6Y2X
public class FileAccessI implements Serializable{ g2OnLEF]s
$LP(\T([
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }m:paB"3
RandomAccessFile oSavedFile; x39tnf/F
long nPos; ,NO[Piok
Bm~^d7;Cw
hY)zKX_r
public FileAccessI() throws IOException &4Z8df!
{ r=j?0k '}]
this("",0); >+O0W)g{o
} b8!oZ~K
|nMjv]#
}Qo]~/
public FileAccessI(String sName,long nPos) throws IOException 0\mf1{$"!7
{ Fe8X@63
oSavedFile = new RandomAccessFile(sName,"rw"); z~{08M7
this.nPos = nPos; g;l K34{
oSavedFile.seek(nPos); ; _%zf5;'
} GMU!GSY
\8(Je"S
:tWkK$
public synchronized int write(byte[] b,int nStart,int nLen) xI,3(A.
{ }B%9cc
int n = -1; d=1\=d/K
try{ W@"Rdc-
oSavedFile.write(b,nStart,nLen); RHsVG &<j
n = nLen; FQek+[ox
} A&}]:4@{
catch(IOException e) 1 |z4]R,<
{ J;sQvPHV8
e.printStackTrace (); '`8 ^P
} % J\G[dl
65Z}Hf
<*vR_?!
return n; p3_ Qx
} RIkIE=+6
\p:)Cdn
rDl/R^w"
} o0WwlmB5
SY95s
4{>r_^8
/* OX,em Ti
**SiteInfoBean.java .QY>@b\
*/ A":=-$)
package NetFox; hq"nRH
IAA_Ft
27}:f?2hbJ
public class SiteInfoBean { &wQ<sVQ0$
r@JMf)a]
PY|zN|
private String sSiteURL; //Site's URL R(t%/Hvs$
private String sFilePath; //Saved File's Path FM%WMyb[
private String sFileName; //Saved File's Name |keU+De
private int nSplitter; //Count of Splited Downloading File 6Takx%U
dkC_Sh{
U| yt
public SiteInfoBean() h0-.9ym
{//nSplitter的缺省值为5 ju:}%'
//default value of nSplitter is 5 _9-;35D_
this("","","",5); 3 85qQppz
} _I)TO_L;
p7+>]sqX
6r^ZMW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `]]m$
{ YS4"TOFw
sSiteURL= sURL; =f@71D1
sFilePath = sPath; ;+DMv5A "
sFileName = sName; ZYY`f/qi
this.nSplitter = nSpiltter; _e8Gt6>
`C7pM
K}q5,P(
} E*R-Dno_F
g[y&GCKY!=
nzO-\`40
public String getSSiteURL() ?gu!P:lZS
{ @WXRZEz
return sSiteURL; F)=<|,b1
} 1z; !)pG.
5T"h7^}e
O*2{V]Y @
public void setSSiteURL(String value) (^T}6t3+4
{ jn]l!nm
sSiteURL = value; AN,3[Sh
} FYNUap,A
j0F& WKk
R {-M%n4w
public String getSFilePath() sw$JY}Q8x
{ R0w~ Z
return sFilePath; M~X~2`fFH
} l"&iSq!3=
W`[7|8(6!
sj+ )
public void setSFilePath(String value) H>\lE2
{ }If,O
sFilePath = value; $/u.F;
} )+)qFGVz
0/fwAp
/^i_tLgb
public String getSFileName() 17:7w
{ 9e;{o,r@
return sFileName; t}K8{ V
} G]-\$>5R
mmC MsBfL
\*fXPJ4
public void setSFileName(String value) fTy{`}>
{ gYpFF=7j<@
sFileName = value; Kk% IN9
} m9'bDyyK
$?&distJ
wLq#,X>%B
public int getNSplitter() T[ zEAj
{ 5uM`4xkj
return nSplitter; ;P8.U(
} Fe2iG-ec
<P5 7s+JK
%u?A>$Jn
public void setNSplitter(int nCount) M\08 7k
{ }dq)d.c
nSplitter = nCount; H/0b3I^
} R|\kk?,u
} AB.ZmR9|
bz\nCfU
oJc v D
/* 9KU3)%U
**Utility.java :Q;mgHTNz
*/ y<ZT~e
package NetFox; A2nL=9~
V4<f4|IL
:<6gP(
public class Utility { ZyrVv\'
2 o5u02x
2Gc0pBqx
public Utility() %G,d&%f
{ .|LY /q\A
ZGS4P0$
)5<c8lzp
} 8J0#lu
E7U.>8C
//线程睡眠 l Ztw[c
public static void sleep(int nSecond) )jH|j
{ XAUHF-"WE
try{ 2()/l9.O'
Thread.sleep(nSecond); <xD6}h/
} t|59/R
catch(Exception e) N}\3UHtO
{ X> V`)
e.printStackTrace (); Gr|102
} HA;G{[X
} d?jzh1
GOY!()F
//日志 Z7=k$e
public static void log(String sMsg) xU;Q~(
{ }\.Z{h:t ?
System.err.println(sMsg); 7HQ|3rt
} 10..<v7
oN.#q$\` k
RA:3ZV
public static void log(int sMsg) e8hwXz
{ >^adxXw.o
System.err.println(sMsg); {Nny.@P)H
} 7G &I]>
} yq\p%z$:
(b;*8
6%fF6
/* &265 B_'D
**TestMethod.java "/$2oYNy+
*/ 4{Af 3N
package NetFox; [BKX$A:Y
\[W)[mH_
NmZowh$M
public class TestMethod { rnS&^
b=Oec%Adx
;n;bap
public TestMethod() s(shgI 3g
{ ///xx/weblogic60b2_win.exe _Xzl=j9[
try{ ^Qa!{9o[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y-#01Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;]sbz4?
SiteFileFetch fileFetch = new SiteFileFetch(bean); [mA\,ny9
fileFetch.start(); (|.rEaTA[1
} .%T.sQ
catch(Exception e){e.printStackTrace ();} OCN@P+L3q
Mib<1ZM
8AuOe7D9A
} ZBl!7_[_
e)A-.SRiO$
U6yZKK
public static void main(String[] args) w4(g]9^Q
{ 'fr~1pmx#3
new TestMethod(); H&E3RU>`
} ^%jk.*
} F%^)oQT+c
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