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)); 1S26Y|L)
} SWGD(]}uz
for(int i=0;i<nEndPos.length-1;i++) %: .{?FB_
{ /P-Eg86V'
nEndPos = nStartPos[i+1]; umo@JWr
} fsDwfwil*
nEndPos[nEndPos.length-1] = nFileLength; CN"hx-f
} ugI9rxT]Kv
} ]2Q:&T
yHL5gz@k
}7H8Y}m
//启动子线程 3h|:ew[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bkgJz+u
for(int i=0;i<nStartPos.length;i++) L--(Y+vmf
{ \%!~pfM I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \dz@hJl:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), eHjn<@
nStartPos,nEndPos,i); rHWlv\+Nn
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pwvcH3l/r
fileSplitterFetch.start(); '~ {xn
} Lz9t9AoB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q< q&a8~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "x*5g*k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oT\u^WU
nEndPos = " + nFileLength); -b4#/q+bb+
// fileSplitterFetch[nPos.length-1].start(); LJ|2=lI+jb
e:~r_,K
iJrF$Xw
//等待子线程结束 !L#>wlX)
//int count = 0; 9w=GB?/
//是否结束while循环 -&ic%0|f
boolean breakWhile = false; rK\)
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t TAqln|
while(!bStop) !Bv"S0
{ H-sJt:
write_nPos(); 1.Ximom
Utility.sleep(500); 8SGFzb! h
breakWhile = true; BF_R8H,<%
RG)!v6
@KhDQ0v]5
for(int i=0;i<nStartPos.length;i++) (,gpR4O[
{ >*PZ&"}M
if(!fileSplitterFetch.bDownOver) v){&g5djl
{ f(h nomn
breakWhile = false; &O'6va
break; gqje]Zc<
} lKMOsr@l
} y0d a8sd)
if(breakWhile) E2s lpo
break; D9;2w7v
DJ)z~W2I*
RN1q/H|
//count++; +%'S>g0W=
//if(count>4) cVt MCgx
// siteStop(); ]Fc<%wzp
} }jQxwi)
"i\rhX
93-UA.+g
System.err.println("文件下载结束！"); R7o3X,-iwn
} * ?a-m\
catch(Exception e){e.printStackTrace ();} n4cM /unU
} w~NQAHAvo
7|IOn5
E*ug.nxy
//获得文件长度 K 9ytot
public long getFileSize() ?v-( :OF
{ RnN]m!"5
int nFileLength = -1; JM-spi o
try{ ,m-z D
URL url = new URL(siteInfoBean.getSSiteURL()); ?mJNzHrq;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cuO)cj]@e
httpConnection.setRequestProperty("User-Agent","NetFox"); NW'rqgG
Q2c|sK8
ccc*"_45#
int responseCode=httpConnection.getResponseCode(); (5s$vcK
if(responseCode>=400) ieN}Ajl2
{ 0UEEvD5
processErrorCode(responseCode); v)*/E'Cr*
return -2; //-2 represent access is error W0X/&v,k*
} {8)Pke
7cGc`7
=/Ob kVYf
String sHeader; `.dX@<
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j {w'#x,
for(int i=1;;i++) U{vt9t
{ g]IRv(gDh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); la7VeFT
//Utility.log(in.readLine()); '~HCYE:5
sHeader=httpConnection.getHeaderFieldKey(i); 7~@9=e8G
if(sHeader!=null) ?MT V!i0
{ O,`#h*{N
if(sHeader.equals("Content-Length")) @l)HX'z0d
{ 2D;,'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); w-%V9]J1
break; b'9\j.By
} <9JI@\>
} (!72Eaw:]
else .E'Tfa
break; WoVPp*zlX
} M ABrf`<b
} "HCJ!
catch(IOException e){e.printStackTrace ();} cFcn61x-
catch(Exception e){e.printStackTrace ();} rBd}u+:*
v71j1Q}6
"P)f,n
Utility.log(nFileLength); &vf9Gp+MK
!_Z\K$Ns
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return nFileLength; I}djDtJ
} SV2DvrIR
+gZg7]!Z
{tUjUwhz(
//保存下载信息（文件指针位置） &cDLSnR
private void write_nPos() Hc`)Q vFRW
{ !~+"TI}_%w
try{ 'R&Y pR
output = new DataOutputStream(new FileOutputStream(tmpFile)); X]^FHYjhS
output.writeInt(nStartPos.length); ftS^|%p
for(int i=0;i<nStartPos.length;i++) @>Y.s6a
{ : +Na8\d
// output.writeLong(nPos); pCXceNFo
output.writeLong(fileSplitterFetch.nStartPos); +Bg$]~T
output.writeLong(fileSplitterFetch.nEndPos); td*1
} i3bH^WwE&k
output.close(); ^P4q6BW
} ,/?7sHK-0
catch(IOException e){e.printStackTrace ();} Y>Oh]?
catch(Exception e){e.printStackTrace ();} K4\{G
} rI/;L<c
~#z8Q{!O
4+rr3 $AY
//读取保存的下载信息（文件指针位置） bXVH7Fy
private void read_nPos() F];"d0O#5
{ z_Em%X
try{ [1+ o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [BPK0
int nCount = input.readInt(); 4R 9lA
nStartPos = new long[nCount]; b.h:~ATgN
nEndPos = new long[nCount]; Gjhpi5?%8
for(int i=0;i<nStartPos.length;i++) L5(7;
{ RO>3U2
nStartPos = input.readLong(); uY{zZ4iw
nEndPos = input.readLong(); }BTK+Tk8
} 0;Lt
input.close(); ,8=`Y9#
} /WvF}y
catch(IOException e){e.printStackTrace ();} m=g\@&N
catch(Exception e){e.printStackTrace ();} 1(S0hm[ov
} N4]Sp v
]i$<<u
$ z4JUr!m
private void processErrorCode(int nErrorCode) :Ma=P\J W
{ ORVFp]gG
System.err.println("Error Code : " + nErrorCode); >XTDN
} $KSdNFtM)A
GyirE`
VFmG\
//停止文件下载 u'Od~x^z
public void siteStop() T0:%,o
{ I&2)@Zw
bStop = true; }XOTK^YA
for(int i=0;i<nStartPos.length;i++) ~>&Jks_Q
fileSplitterFetch.splitterStop(); 4Ss4jUj
^("23mhfJ
NOC8h\s}(
} {RG4m{#9
} caG5S#8-"
//负责部分文件的抓取 +c7e[hz
**FileSplitterFetch.java kGz0`8URu
*/ Fe r&X
package NetFox; =1kE2u
Hnq$d6F
A_8UPGh8
import java.io.*; %4bGI/\/
import java.net.*; z%FBHj
Z<P?P`
|M8FMH[_
public class FileSplitterFetch extends Thread { ;u:A:Y4V
~J~@mE2ks
xE$>;30b_
String sURL; //File URL L=7Y~aL=
long nStartPos; //File Snippet Start Position y cT@D/
long nEndPos; //File Snippet End Position L<7KmN4VX
int nThreadID; //Thread's ID -0I]Sm;$
boolean bDownOver = false; //Downing is over Rcn6puZt
boolean bStop = false; //Stop identical `, lnBP3D"
FileAccessI fileAccessI = null; //File Access interface wBuos}/
u&M:w5EM
+'-i(]@!'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6dH> 0l
{ (+(YQ2
this.sURL = sURL; .eBo:4T!d
this.nStartPos = nStart; 4!vovt{
this.nEndPos = nEnd; 4](jV}Hg
nThreadID = id; DB=^Z%%Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }s@ i
} \!51I./Q/
iBqxz:PHN(
c"wk_#
public void run() rtjUHhF
{ 0:1[F!]'b
while(nStartPos < nEndPos && !bStop) S17iYjy#8T
{ E;o "^[we
K/flg|uZ/V
-XJXl}M.
try{ a<E\9DL
URL url = new URL(sURL); M~?2g.o'D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jqzG=/0~{
httpConnection.setRequestProperty("User-Agent","NetFox"); 6"o,)e/z
String sProperty = "bytes="+nStartPos+"-"; T)Uhp
httpConnection.setRequestProperty("RANGE",sProperty); ,(;TV_@$
Utility.log(sProperty); 8wf[*6VwV
kndN} Vq
>D\jyd$wh&
InputStream input = httpConnection.getInputStream(); mXSs:FqE!
//logResponseHead(httpConnection); L*(!P4S%}
1B0+dxN`
["u:_2!4P
byte[] b = new byte[1024]; j}`XF?2D
int nRead; <rKfL`8p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FjU -t/
{ a>o]garB+
nStartPos += fileAccessI.write(b,0,nRead); WC7ltw2
//if(nThreadID == 1) ML!>tCT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6)]zt
} |34M.YjA
5/E7@h ,
2lu AF2
Utility.log("Thread " + nThreadID + " is over!"); )N'-Ap$g
bDownOver = true; n>XfXt =
//nPos = fileAccessI.write (b,0,nRead); *SmR|Qy
} ,hVDGif
catch(Exception e){e.printStackTrace ();} NMvNw?]
} /8O;Q~a
} UhX)?'J
Zk+c9,q
`9`T,uJe
//打印回应的头信息 ?*/1J~<(@
public void logResponseHead(HttpURLConnection con) p Lwtm@
{ olxnQYFo
for(int i=1;;i++) FoW|BGA~
{ xbNL <3"a
String header=con.getHeaderFieldKey(i); C}=9m A
if(header!=null) +HSKFp
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s#p\ r
Utility.log(header+" : "+con.getHeaderField(header)); /D>G4PP<
else n8.Tag(#
break; K/l*Saj
} TN=!;SvQU
} Zsto8wuf#
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0% zy 6{
public void splitterStop() 9=}&evGm89
{ /=@V5)
bStop = true; |44 E:pA
} C@P*:L_
_@D"XL#L
[Te"|K':
} IJk<1T7:(W
2uzy]faM
>$:_M*5
/* nJ|M
**FileAccess.java d "%6S*dL
*//文件访问(定位，写) ]j+J^g
package NetFox; 8D&yFal
import java.io.*; SH5a&OVZhn
1~ZFkcV_C
6R|^IPOGp
public class FileAccessI implements Serializable{ hkDew0k
5_+pgJL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 D16w!Mnz{K
RandomAccessFile oSavedFile; 2I>`{#fV
long nPos; r:U/a=V
MWI7u7{
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public FileAccessI() throws IOException .!)i
{ a^7HI,
this("",0); uWkn}P
} !-~sxa280r
2rWPqG4e
NRMEZ\*L
public FileAccessI(String sName,long nPos) throws IOException +GL[uxe"
{ #:xv]qb`k
oSavedFile = new RandomAccessFile(sName,"rw"); Zo#c[9IaC
this.nPos = nPos; |.?Xov]
oSavedFile.seek(nPos); Y<;KKD5P'j
} fn, YH
%cl{J_}{&
6){nu rDBG
public synchronized int write(byte[] b,int nStart,int nLen) ,FK.8c6g
{ <AN5>:k[pM
int n = -1; E[Bj+mX9
try{ Ov@vNj&
oSavedFile.write(b,nStart,nLen); j_0xE;g"]
n = nLen; }q=tg9
} $QnsP#ePN
catch(IOException e) 6 2LLfD
{ Vtv1{/@+c
e.printStackTrace (); #b@ sV$
} i$6o>V6
.\7AJB\l
}$` PZUw>
return n; W=I~GhM
} Wrf+5 ;,,
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JOo+RA5d
} `RyH~4\;
"%ZAL\x
MogIQ
/* KtcuGI/A
**SiteInfoBean.java 3oM&#a
*/ tR<L9h
package NetFox; qHu\3@px
g4Nl"s*~
fF^A9{{BS
public class SiteInfoBean { XBm ^7'
C1x(4&h
y]}N[l
private String sSiteURL; //Site's URL kC iOcl*$
private String sFilePath; //Saved File's Path KidbcZ
private String sFileName; //Saved File's Name AWDy_11Nm
private int nSplitter; //Count of Splited Downloading File 0QY9vuhL<
N>IkK*v
BeFXC5-qat
public SiteInfoBean() \t]_UNGyW
{//nSplitter的缺省值为5 x$) E^|A+
//default value of nSplitter is 5 +&[X7r<
this("","","",5); Z@i,9 a
} = ,c!V
k1fX-2H
"DSRyD0M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9P*p{O{_
{ 1"No~/_
sSiteURL= sURL; I+rLKGZC
sFilePath = sPath; fv:&?gc
sFileName = sName; h]WW?.
this.nSplitter = nSpiltter; ,p V3O`z
I^m9(L4%
I\f\k>;
} y'_2|5!Qs
&R3#? 1,
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public String getSSiteURL() sOm&7A?
{ {j%7/T{
return sSiteURL; /\U:F
} Go !{T
`!C5"i8+i2
PoZxT-U
public void setSSiteURL(String value) FO)`&s"&2
{ wu3p2#-Z
sSiteURL = value; ztC>*SX
} \R,8xID_t
)PvB^n
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public String getSFilePath() ,f$ftn\~j/
{ r[P+F
return sFilePath; }LryRcrD-n
} 2U) 0k*
U98e=57N
V82hk0*j
public void setSFilePath(String value) (/C 8\}Ox
{ AQ)J|i
sFilePath = value; #0c;2}D
} lI;ACF^
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~N8$abQJV
public String getSFileName() m{by%
{ YXDuhrs}
return sFileName; ycrM8Mu 3
} MI>_wG5P@
HxNoV.q
!Aw.)<teW
public void setSFileName(String value) R T/)<RT9
{ ]%+T+zg(Y
sFileName = value; /|8/C40aY
} <X ([VZ
._6e#=
7%5EBH &
public int getNSplitter() HAAU2A9B2
{ Wo~;h(6
return nSplitter; g1&q6wCg|
} > mEB,
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lMe+.P|
public void setNSplitter(int nCount) S^nI=HTm
{ >~})O&t
nSplitter = nCount; Ly]J-BTe
} WT:ZT$W
} :~'R|l
ITfz/d8
?cB26Zrcb
/* {=9"WN
**Utility.java (1Klj+"p%
*/ dg4q+
package NetFox; FBS]U$1
9/dADJe0b
e,T^8_>
public class Utility { qD{~QHDa
_c,{}sn
wpcqgc
public Utility() QZFH>,d
{ 4}Yn!"jW&
I[bWd{i:
af|x(:!H
} 41I2t(H @z
$8>II0C.
//线程睡眠 wS+j^ ;"
public static void sleep(int nSecond) 0}WDB_L
{ 7|(o=+Bt
try{ ~r&+18Z;
Thread.sleep(nSecond); +Os9}uKf
} t<MO~_`!
catch(Exception e) bCV_jR+
{ bOD]`*q
e.printStackTrace (); hZ-?-F?*@
} sU"sd7#A
} UL`%Xx
h}=
//日志 VCa`|S?2
public static void log(String sMsg) K1zH\wH
{ q:9CFAX0=
System.err.println(sMsg); .yQ<
} EKNmXt1 lE
N[;R8SP
!YX_k<1E
public static void log(int sMsg) 9}'92
{ ebhV;Q.
System.err.println(sMsg); -AwkP
} ^>#@qMw
} xPzBbe
9EWw
@P<aTRy,f
/* dlBr2 9
**TestMethod.java N[kl3h%q
*/ lCGEd 3
package NetFox; %:\GYs(Y
=,Z5F`d4
HEm XB=
public class TestMethod { Wcki=ac\v!
x| r#
.qrS[ w
public TestMethod() G'mg-{
{ ///xx/weblogic60b2_win.exe na_Wp^;
try{ t""d^a#Dp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); yQ| V7G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (1)b> 6
SiteFileFetch fileFetch = new SiteFileFetch(bean); lF~!F<^9
fileFetch.start(); R/l/GNm
} #BX}j&h_
catch(Exception e){e.printStackTrace ();} *.!5327
o&Y R\BI/
|N:kf&]b
} '}F..w/
'SKq<X%R;
SyIi*dH
public static void main(String[] args) Nh1, w
{ *kt%.wPJ
new TestMethod(); fr8hT(,s)
} T*92o:^
} ;I~UQgE6H
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