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)); b4ONh%
} iBgx
for(int i=0;i<nEndPos.length-1;i++) YCM]VDx4u1
{ :'l^kSP_*C
nEndPos = nStartPos[i+1]; !~D}/Q;#}\
} \\dMy9M-
nEndPos[nEndPos.length-1] = nFileLength; i||]V*5n
} M`i\VG
} {|:;]T"y
c%G{#}^2
@A89eZbW
//启动子线程 LS*y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &wCg\j_c
for(int i=0;i<nStartPos.length;i++) ;J2zp*|
{ ZR?yDgL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EYEnN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /qGf 1MHD
nStartPos,nEndPos,i); &*G#H~\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9:1Q1,-i!-
fileSplitterFetch.start(); QpA/SmJ
} ( _)jkI \
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), giIWGa.a+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,TN 2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,>-< (Qi
nEndPos = " + nFileLength); 1Z~)RJ<D
// fileSplitterFetch[nPos.length-1].start(); p@5`&Em,
tlqiXh<
e`TH91@
//等待子线程结束 C:C}5<fkx
//int count = 0; )V6Hl@v
//是否结束while循环 X/2&!O
boolean breakWhile = false; Z99>5\k
Q[pV!CH
vUU9$x
while(!bStop) L=8<B=QT$
{ 6%Pdy$ P
write_nPos(); 0#&5.Gr)
Utility.sleep(500); J/GSceHF
breakWhile = true; xScLVt<\e
af+IP_6 .
7Kal"Ew
for(int i=0;i<nStartPos.length;i++) #9xd[A: N
{ hKjt'N:~ZY
if(!fileSplitterFetch.bDownOver) g,95T Bc
{ h`k"A7M
breakWhile = false; T}P".kpbS
break; H_ox_ u}
} xp72>*_9&
} k |%B?\m
if(breakWhile) be-~\@
break; mkF"
?zVL;gVWA
wl$h4 {L7
//count++; D-(w_$#
//if(count>4) q+]h=:5=I
// siteStop(); (%xwl
} &c%g
okv1K
BT"42#7_
System.err.println("文件下载结束！"); rT5Ycm@
} +0q>fp_K(+
catch(Exception e){e.printStackTrace ();} 2e9es
} }S$@ Ez6
_DNHc*
ugx%_x6
//获得文件长度 LLXVNO@e+
public long getFileSize() .j>hI="b
{ Ej>g.vp8I
int nFileLength = -1; I=9!Rs(QF
try{ p4i]7o@
URL url = new URL(siteInfoBean.getSSiteURL()); -3lb@ 6I6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 09kt[
httpConnection.setRequestProperty("User-Agent","NetFox"); S'B|>!z@
/3:q#2'v
OP|8Sk6 r
int responseCode=httpConnection.getResponseCode(); )V:]g\t
if(responseCode>=400) deixy. |
{ -!L"')
processErrorCode(responseCode); `zt_7MD
return -2; //-2 represent access is error jDN ]3Y`
} -7&Gi +]
0`A~HH}
!i%"7tQ3$
String sHeader; BC;:
]&{ci
,qrQ"r9
for(int i=1;;i++) g{9+O7q
{ ^e>Wo7r
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lmSo8/%T
//Utility.log(in.readLine()); 4[-*~C|W5
sHeader=httpConnection.getHeaderFieldKey(i); >ap1"n9k
if(sHeader!=null) dG71*)<)t
{ ^~HQC*
if(sHeader.equals("Content-Length")) {; >Q.OX@
{ ^F"iP7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e=QK}gzX
break; ~E^,=4
} rzI|?QaPi
} vuFBET,
else UD y(v]
break; R?EASc!b
} $VQtwuYt
} ) (Tom9^
catch(IOException e){e.printStackTrace ();} `H3.,]
catch(Exception e){e.printStackTrace ();} X*7\lf2
$CE[MZ&S
eVcANP
Utility.log(nFileLength); J!*/a'Cv
LR,7,DH$9'
|J~eLh[d
return nFileLength; #s%-INcR
} O!Z|r?
nD2,!71
5]1h8PW!Y
//保存下载信息（文件指针位置） R, 8s_jN
private void write_nPos() 1lnU77;
{ 8g>b
try{ .~gl19#:T
output = new DataOutputStream(new FileOutputStream(tmpFile)); *X38{rj
output.writeInt(nStartPos.length); j` /&r*zNq
for(int i=0;i<nStartPos.length;i++) 8Z2.`(3c[
{ do ^RF<G
// output.writeLong(nPos); OW(&s,|6x
output.writeLong(fileSplitterFetch.nStartPos); N|2y"5
output.writeLong(fileSplitterFetch.nEndPos); +/+P\O
} #DkD!dW(l
output.close(); &wetzC)
} t%r :4,
catch(IOException e){e.printStackTrace ();} O8N[Jl
catch(Exception e){e.printStackTrace ();} v}v 5
} 0X(]7b&~R
L{ymI)Y^
vY*\R0/a
//读取保存的下载信息（文件指针位置） wn11\j&
private void read_nPos() W:QwHZ2O
{ sxED7,A
try{ $YG1z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [[)_BmS5r
int nCount = input.readInt(); ~L+]n0*
nStartPos = new long[nCount]; NgB 7?]vu
nEndPos = new long[nCount]; +TRy:e
for(int i=0;i<nStartPos.length;i++) I2HT2c$
{ \`xkp[C
nStartPos = input.readLong(); u>Ki$xP1
nEndPos = input.readLong(); S C_|A9
} >AI<60/<
input.close(); }IlP:
} YbMssd2Yg
catch(IOException e){e.printStackTrace ();} 1ZKzumF
catch(Exception e){e.printStackTrace ();} C/v}^#cLD
} j:1uP^.
O(OmGu4%
i.rU&yT%
private void processErrorCode(int nErrorCode) V_L[P9
{ CM~MoV[k7e
System.err.println("Error Code : " + nErrorCode); -'C!"\%
} amB@N6*
G+Dpma ]
*PM}"s
//停止文件下载 GzdgL"M[
public void siteStop() &P n]
{ ,sb1"^Wc
bStop = true; Rk<%r k
for(int i=0;i<nStartPos.length;i++) {~GR8 U
fileSplitterFetch.splitterStop(); MtG_9-
K~>jApZ%
_9h.Gt
} $au2%NL
} @ u1Q-:
//负责部分文件的抓取 ?*K<*wBw#
**FileSplitterFetch.java .k]#XoE
*/ 4 10:%WGc
package NetFox; OKQLv+q5K)
<-|SIF
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import java.io.*; glor+
import java.net.*; 31 ]7z
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public class FileSplitterFetch extends Thread { Ve14rn
j<$R4A1
A[ 1)!e
String sURL; //File URL d[U1.SNL
long nStartPos; //File Snippet Start Position FR'b`Xv:
long nEndPos; //File Snippet End Position ^I./L)0=}
int nThreadID; //Thread's ID -y8?"WB(b
boolean bDownOver = false; //Downing is over 6cCC+*V{
boolean bStop = false; //Stop identical ^Vl{IsY
FileAccessI fileAccessI = null; //File Access interface aY^_+&&G
67Z.aaXD1
] ~;x$Z)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException __}j {Buk
{ v&[Ff|>
this.sURL = sURL; 93zoJiLRf
this.nStartPos = nStart; JEF2fro:Z
this.nEndPos = nEnd; N# Ru`;
nThreadID = id; ,W"[q~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vT*z3
} Vb0((c%&
_Y7uM6HL\
`"N56
public void run() "3kIQsD|j
{ ?v]EXV3
while(nStartPos < nEndPos && !bStop) ] m$;ra]
{ NaeG2>1
kaSy 9Y{
nLn3kMl4
try{ 58x=CN\QU
URL url = new URL(sURL); y.$/niQ%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VdrqbZ
httpConnection.setRequestProperty("User-Agent","NetFox"); LKCj@NdV
String sProperty = "bytes="+nStartPos+"-"; o6JCy\Bx
httpConnection.setRequestProperty("RANGE",sProperty); MfJ;":]O!
Utility.log(sProperty); L&[uE;ro
3P{ d~2
Pr |u_^
InputStream input = httpConnection.getInputStream(); 9M3XHj
//logResponseHead(httpConnection); |@{4zoP_N
~x:\xQti
sEpY&6*
byte[] b = new byte[1024]; FerQA9K)x
int nRead; RR,gC"cTi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ao2NwH##
{ T%{qwZc+mJ
nStartPos += fileAccessI.write(b,0,nRead); 1P(5+9"s
//if(nThreadID == 1) MeD}S@H
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vM_UF{a$=
} :#CQQ*@
c&!EsMsU
)f#raXa5+
Utility.log("Thread " + nThreadID + " is over!"); +n]z'pijb
bDownOver = true; [1pWg^
//nPos = fileAccessI.write (b,0,nRead); 13+f ^
} JQ-O=8]
catch(Exception e){e.printStackTrace ();} L9,;zkgo
} 60 D0z
} *G'R+_tdE
N3J T[7
iUNlNl ?
//打印回应的头信息 3em&7QM
public void logResponseHead(HttpURLConnection con) " 3ryp A
{ r]GG9si
for(int i=1;;i++) M1{ru~Z9
{ ,ALEfepo
String header=con.getHeaderFieldKey(i); F+%6?2J
if(header!=null) Ie12d@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PVK. %y9
Utility.log(header+" : "+con.getHeaderField(header)); Y9YE:s
else ^0 zWiX
break; _J|cJ %F>%
} 0rnne L
} lCyBdY9n
oP[R?zN
$2tPqZ>
public void splitterStop() B,2oA]W"S
{ y(^hlX6gQ
bStop = true; /' +GYS
} UEm~5,>$0
S,Y\ox-
x{GKz#
} Z@Tb3N/[
{x&"b-
@;^7kt
/* #YABbwH
**FileAccess.java WUEjWJA-MB
*//文件访问(定位，写) 1[? xU:;9
package NetFox; pwu8LQ3b{O
import java.io.*; ]]R!MnU:$
Iu3*`H
h'QEwW
public class FileAccessI implements Serializable{ N:4oVi@Je
\A~r~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E%+aqA)f
RandomAccessFile oSavedFile; e*nT+Rp
long nPos; <@+>A$~0
@bkZ< Gq
{c#{dT
public FileAccessI() throws IOException Y6&B%t<bo
{ !623;
this("",0); CrTGC%w{=
} E0SP
yf lt2 R
dg(fD>+
public FileAccessI(String sName,long nPos) throws IOException 7KB:wsz^
{ |=\w b^l+
oSavedFile = new RandomAccessFile(sName,"rw"); Z'u:Em
this.nPos = nPos; W7sx/O9
oSavedFile.seek(nPos); BAJEn6f?
} #iZ%CY\
A_:YpQ07@
8J5{}4s\f
public synchronized int write(byte[] b,int nStart,int nLen) @P$_2IU"
{ =7*k>]o
int n = -1; {H\(H_X
try{ >$%rsc}^
oSavedFile.write(b,nStart,nLen); +A=*C
n = nLen; NHL -ll-R
} _&]B
catch(IOException e) 9=-d/y?
{ O<:"Irq\qr
e.printStackTrace (); -0tHc=\u(
} P ~sX S
V~9s+>
DGQGV[9%4C
return n; YNRorE
} nw)yK%`;M
"1#piJ
9q4%s?)j
} pyf/%9R:d
4ox[,
;I#f:UQ
/* M?3Nh;
**SiteInfoBean.java 'f?=ks<
*/ 7Zf *T
package NetFox; AJ:(NV1=
Q&X#(3&'
G<8d=}
public class SiteInfoBean { Q;'{~!=
o-m9}pV
I'qIc?
private String sSiteURL; //Site's URL 2,3pmb
private String sFilePath; //Saved File's Path %]iDhXLr
private String sFileName; //Saved File's Name +im>|
private int nSplitter; //Count of Splited Downloading File !n?8'eqWru
^e1Ux
`E4+#_ v
public SiteInfoBean() q>E[)\+y
{//nSplitter的缺省值为5 Hl3%+f
//default value of nSplitter is 5 : }q~<
this("","","",5); v'vYNh
} 6^'BhHP
{tN?)~ZQ
S%sD#0l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L2L=~/LG
{ 8}^R jMgI
sSiteURL= sURL; k'(eQ5R3L
sFilePath = sPath; t@Bl3Nt{
sFileName = sName; 4fq:W`9sN
this.nSplitter = nSpiltter; k|SywATr
mbS`+)1=l
CHojF+e
} !UV1OU
wt(Hk6/B
)v+R+3<
public String getSSiteURL() ?c;T4@mB
{ ?C6DK{S(
return sSiteURL; z^etH/]Sy
} icw (y(W
*2(W`m
43HZ)3!me
public void setSSiteURL(String value) 'WC> _L
{ us0{y7(p
sSiteURL = value; %^?yI
} A@o:mZ+XN(
4L`<xX;:{
M#?^uu'
public String getSFilePath() ydx-`yg#
{ jO9w7u6
return sFilePath; c'XvZNf .C
} qVidubsW
-UMPt"o
?L'4*S]
public void setSFilePath(String value) pT;{05
{ s&gzv=v
sFilePath = value; dPtQ Sa
} +,H6)'#Z
B4>kx#LR
CB1AL]|3
public String getSFileName() wRATe 0'
{ @ a$HJ:
return sFileName; K5ywO8_6`
} IdzrQP
M.loG4r!
*@C]\)
public void setSFileName(String value) +I9+L6>UR
{ 2o\GU
sFileName = value; Z ^w5x:
} JBCJVWUt
;Bs^+R7
eT4+O5t
public int getNSplitter() #SR"Q`P
{ F[65)"^
return nSplitter; DKzP)!B "
} :q+D`s
jxt^d
2Q/#.lNL
public void setNSplitter(int nCount) GkutS.2G#
{ vcsMU|GGh
nSplitter = nCount; rf%NfU
} T&5dF9a
} <>&!+|#
fV`R7m.
B3Yj
/* t\p_QWnF
**Utility.java v8<MAq
*/ dF-d
package NetFox; `T;M=S^y*E
?b&~(,A{
-i}@o1o\
public class Utility { &;)6G1X1
/wjL<
>H,t^i}@
public Utility() D-zqu~f`
{ @Lj28&4:<
$jDp ^ -
<( 0TK5
} aXSTA,%
.-:R mYGR
//线程睡眠 <.d0GD`^
public static void sleep(int nSecond) {FavF 9O
{ ^c9~~m16+
try{ fRTQ5V
Thread.sleep(nSecond); xY/ S;dE
} w:}RS.AK
catch(Exception e) uQ;b'6Jcp
{ XG5mfKMt+
e.printStackTrace (); e/?>6'6 5
} y`~[R7E
} =9oN#4mWK
C#5z!z/:%
//日志 Hm?zMyO.k
public static void log(String sMsg) kpkN GQ2
{ Ou _bM n
System.err.println(sMsg); ]hBp elKJ
} Um k9
@x>J-Owd]J
c%uX+\-$
public static void log(int sMsg) %} _{_Z
{ -P09u82
System.err.println(sMsg); 1RtbQ{2F;
} [Hn4&PET
} gE/O29Y
/{.
#:v e3gWl
/* 7W[}7Y
**TestMethod.java "28b&pm
*/ ,y[wS5li
package NetFox; 9L}=xX`>?
h Znq\p~
d/8I&{.
public class TestMethod { ?hh4M
2$^n@<uZ@
R=IZFwr
public TestMethod() C?e1 a9r
{ ///xx/weblogic60b2_win.exe DiyviH
try{ n>tYeN)F<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *5k" v"NM(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); M`$s dZ"
SiteFileFetch fileFetch = new SiteFileFetch(bean); QvK-3w;=
fileFetch.start(); e9;<9uX
} O_#Ag K<A
catch(Exception e){e.printStackTrace ();} <wge_3W#
sO~:e?F
oagxTFh8~
} K.?~@5%
'dYjbQ}~;
TY[1jW~{r
public static void main(String[] args) Kd8V,teH
{ j?ihUNY!+
new TestMethod(); D!kv+<+
} JPQ[JD^]
} q1sK:)Hu+
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