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)); J1RJ*mo7,
} GmEJhr.3`=
for(int i=0;i<nEndPos.length-1;i++) cyv`B3}
{ Z=Y& B>:[
nEndPos = nStartPos[i+1]; 6@ IXqKz
} )SRefW.v
nEndPos[nEndPos.length-1] = nFileLength; QP8Ei~
} ujq=F
} 6/Xk7B
?;+1)>{
)E@.!Ut4o
//启动子线程 "ZoRZ'i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }mq6]ZrK
for(int i=0;i<nStartPos.length;i++) dIa+K?INX
{ " H&W}N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ex9g?*Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #9}D4i.`}
nStartPos,nEndPos,i); u#;7<.D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (%e.:W${
fileSplitterFetch.start(); 2%@4]
} ukfQe }I
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wb5baY9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *,8^@(th
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OSWYGnZg
nEndPos = " + nFileLength); zrL$]Oy}x
// fileSplitterFetch[nPos.length-1].start(); w/S%YW3*
[OV"}<V
," Wr"
//等待子线程结束 Z/;(fL
//int count = 0; >WQMqQ^t@
//是否结束while循环 NI}yVV
boolean breakWhile = false; st3l2Q
EZy)A$|
Ng>5?F^v
while(!bStop) l7259Ro~
{ 7BjJhs
write_nPos(); (Hz^)5(~
Utility.sleep(500); ZaDyg"Tw+
breakWhile = true; # 448-8x
C]eSizS.
4Lh!8g=/
for(int i=0;i<nStartPos.length;i++) [.8BTj1%
{ %C'?@,7C
if(!fileSplitterFetch.bDownOver) YpZ+n*&+
{ W5lR0)~#*
breakWhile = false; H*QIB_
break; zyc"]IzOU
} c~$)UND^
} o]` *M|
if(breakWhile) djQH1^(IU
break; 4(~L#}:r!
gA5/,wDO
] =xE
//count++; 7he,?T)vD
//if(count>4) T`.O'!
// siteStop(); Lh"<XYY
} f/NH:1)y
+0%w ;'9z
Z!#!Gu*V
System.err.println("文件下载结束！"); 1N^[.=
} ^f &XQQY
catch(Exception e){e.printStackTrace ();} #`iB`|
} .hP D$o
I^]2K0+x x
yw[g!W
//获得文件长度 NP#w+Qw
public long getFileSize() /k6MzFoid
{ *{@Nq=fE
int nFileLength = -1; u\x}8pn
try{ *@r/5pM2}
URL url = new URL(siteInfoBean.getSSiteURL()); dvx#q5f_S
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ooL!TSGD
httpConnection.setRequestProperty("User-Agent","NetFox"); bv9]\qC]T<
}[};IqVaK
.E1rqBG
int responseCode=httpConnection.getResponseCode(); <#y[gTJ<'>
if(responseCode>=400) 88gM?G _X
{ gQelD6c
processErrorCode(responseCode); [0[i5'K:
return -2; //-2 represent access is error H8^(GUhyp
} eRstD>r
e&F8m%t
vnt%XU,,Y
String sHeader; 5 +YH.4R
]^n7
N1S{suic
for(int i=1;;i++) vq0Tk bzs
{ 2dcV"lY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E`0?
//Utility.log(in.readLine()); C8:f_mJU
sHeader=httpConnection.getHeaderFieldKey(i); r1m]HFN
if(sHeader!=null) ]z;I_-
{ /?'FE 7Y
if(sHeader.equals("Content-Length")) #7$ H
{ eIEeb,#i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q&-`,8#
break; |`,2ri*5A
} \fr~
} IH&|Tcf\
else 7P5)Z-K[
break; +wU@ynw
} F>6|3bOR
} =^f<v_L
catch(IOException e){e.printStackTrace ();} FZ<gpIv!NS
catch(Exception e){e.printStackTrace ();} n;C :0
_|\~q[ep
GPv1fearl
Utility.log(nFileLength); LTCb@L{^i
YnS#H"
T_ <@..C
return nFileLength; S9D<8j^
} #PW9:_BE
oUr66a/[U
f4b/NG|
//保存下载信息（文件指针位置） $q{!5-e
private void write_nPos() _QE qk@ql
{ x7w4[QYw
try{ ")5":V~fN
output = new DataOutputStream(new FileOutputStream(tmpFile)); Al^d$FaF
output.writeInt(nStartPos.length); l -mfFN
for(int i=0;i<nStartPos.length;i++) {n.PF8A5X
{ !cLo>,4
// output.writeLong(nPos); 7\[@m3s
output.writeLong(fileSplitterFetch.nStartPos); 8.=BaNU
output.writeLong(fileSplitterFetch.nEndPos); =.U[$~3q%
} q=m'^ ,gPS
output.close(); oj<gD
} $am$EU?s
catch(IOException e){e.printStackTrace ();} Xp% v.M
catch(Exception e){e.printStackTrace ();} wqs?828x
} Hqx-~hQO
e@07
hJ? O],4J
//读取保存的下载信息（文件指针位置） [`[|l
private void read_nPos() #&k5d:
{ JPUW6e07o
try{ ,0Hr2*p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mh#a#<
int nCount = input.readInt(); 4G0m\[Du
nStartPos = new long[nCount]; )}(^, Fo c
nEndPos = new long[nCount]; |O+H[;TB6
for(int i=0;i<nStartPos.length;i++) ) 7@ `ut
{ +oML&g-g_
nStartPos = input.readLong(); gp?uHKsM
nEndPos = input.readLong(); 6ex/TySM
} : /N0!&7
input.close(); /NFj(+&g+
} Fb>?1i`RN
catch(IOException e){e.printStackTrace ();} 1{.|+S Z!
catch(Exception e){e.printStackTrace ();} `?@}>.
} GPudaF{
]Sz:|%JP1
T!kN)#S
private void processErrorCode(int nErrorCode) n\'4
{ 1#2 I
System.err.println("Error Code : " + nErrorCode); MUc$j&
} @ioJ]$o7
E_wCN&`[
6l1jMm|= X
//停止文件下载 g2ixx+`?|:
public void siteStop() Y('#jU
{ hH3RP{'=
bStop = true; {9pZ)tB
for(int i=0;i<nStartPos.length;i++) N!=v4f
fileSplitterFetch.splitterStop(); pa3{8x{9m
OLGE!&!>
7U"g3a)=
} itP,\k7>d
} *#|&JIEsi
//负责部分文件的抓取 _8J.fT$${
**FileSplitterFetch.java p38-l'{#
*/ !;{7-~
package NetFox; HM1Fz\Sf
q~o<*W
:\c ^*K(9
import java.io.*; ie95rZp
import java.net.*; iHf$
&h)yro
SHgN~Um
public class FileSplitterFetch extends Thread { 4l'fCZhA}
ZvX*t)VjTz
]Q1yNtN
String sURL; //File URL _6hQ %hv8
long nStartPos; //File Snippet Start Position F~W6Bp^W
long nEndPos; //File Snippet End Position ueWEc^_>
int nThreadID; //Thread's ID 3(N$nsi
boolean bDownOver = false; //Downing is over NwvC[4
boolean bStop = false; //Stop identical ,/2Vt/lt
FileAccessI fileAccessI = null; //File Access interface xm~`7~nFR
An0|[uWH
\?-<4Bc@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4k1xy##
{ J!(<y(l
this.sURL = sURL; G>}255qY
this.nStartPos = nStart; gZXi]m&
this.nEndPos = nEnd; AV]2euyn
nThreadID = id; my1@41 H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l|[N42+
} *:7rdzn
v!-pSa)3
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public void run() ^uc=f2=>,
{ Ge@{_
while(nStartPos < nEndPos && !bStop) iWkWR"ysy
{ h,N?Ab'S
adcE'fA<_
EME|k{W
try{ ]s'as9s9
URL url = new URL(sURL); u&vf+6=9Dd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Hvi49c]]
httpConnection.setRequestProperty("User-Agent","NetFox"); +\]\[6
String sProperty = "bytes="+nStartPos+"-"; jB2[(
httpConnection.setRequestProperty("RANGE",sProperty); <'Eme
Utility.log(sProperty); g:@#@1rB6
oZgjQM$YP
h(dvZ= %
InputStream input = httpConnection.getInputStream(); ^{`exCwMx
//logResponseHead(httpConnection); .~;\eW[
'H>^2C iM
5C]x!>kX
byte[] b = new byte[1024]; ,&.!?0+
int nRead; !;A\.~-!G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;$|nrwhy
{ PC8Q"O
nStartPos += fileAccessI.write(b,0,nRead); <kqo^
//if(nThreadID == 1) hn@08t G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cV6D<,)
} KV *#T20T
JH9J5%sp
K\r8g=U
Utility.log("Thread " + nThreadID + " is over!"); + &Eqk
bDownOver = true; .L~AL|2_
//nPos = fileAccessI.write (b,0,nRead); (w3YvG.
} 2/^3WY1U
catch(Exception e){e.printStackTrace ();} </zEg3F\
} C,r;VyW6BI
} *i%d,w0+
U8?mc
d7upz]K9g
//打印回应的头信息 UiW>J
public void logResponseHead(HttpURLConnection con) g!|kp?
{ =dKtV.L
for(int i=1;;i++) _B<X`L =
{ rb.N~
String header=con.getHeaderFieldKey(i); #;e:A8IQ
if(header!=null) 6bC3O4Rw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x 9fip-
Utility.log(header+" : "+con.getHeaderField(header)); }my`K
else -Q*gW2KmV
break; 5t]H?b8
} 24eLB?H
} q0vQa
u6JM]kR
~$^XP.a.
public void splitterStop() }Sv:`9=
{ T0)@pt7>
bStop = true; 0GeTSFj
} aW7^d'ZZ\
8l`*]1.W<
#*Ctwl,T
} 4!?eRY
wmLs/:~
F]&*ow
/* +mn[5Y}:
**FileAccess.java q/,O\,
*//文件访问(定位，写) X \/#@T
package NetFox; NBGH_6DROw
import java.io.*; kuP(r
sXPe/fWo
S,he6zS
public class FileAccessI implements Serializable{ t{{QE:/
b\2 ds,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5$k:t
RandomAccessFile oSavedFile; [4f{w%~^
long nPos; j\M?~=*w
?=Kduef
> ~O.@|
public FileAccessI() throws IOException Gd85kY@w7
{ gcT%c|.
this("",0); ?Ir:g=RP*
} ym1Y4,
@q)d
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public FileAccessI(String sName,long nPos) throws IOException nu%*'.
{ wibNQ`4k
oSavedFile = new RandomAccessFile(sName,"rw"); cvL;3jRo
this.nPos = nPos; s~X%Y<9l
oSavedFile.seek(nPos); =I_'.b
} cr;da)
tCt#%7J;a
eaU
public synchronized int write(byte[] b,int nStart,int nLen) Nh44]*
{ ?:0Jav
int n = -1; sYA1\YIii
try{ BI@[\aRLQ
oSavedFile.write(b,nStart,nLen); $I?"lky
n = nLen; >A"(KSNL
} pQB."[n
catch(IOException e) y6BAH
{ V0mn4sfs
e.printStackTrace (); Ny/MJ#Lq
} Mi_$">1-W
)^hbsMhO
?S=mybp
return n; %WS+(0*1
} JBZ@'8eqi]
[:*)XeRK
@=u3ZVD
} ns4,@C$
I>$&-i
OY({.uVdX
/* FS1z`wYP
**SiteInfoBean.java E]r?{t`]
*/ w0unS`\4
package NetFox; |R:'\+E
wMN]~|z>
dPRra{
public class SiteInfoBean { WNc0W>*NE1
*LY8D<:zs
U6s[`H3I{
private String sSiteURL; //Site's URL f|(M.U-
private String sFilePath; //Saved File's Path xT2PyI_:
private String sFileName; //Saved File's Name I]q% 2ie
private int nSplitter; //Count of Splited Downloading File K*dCc}:`
\|[;Z"4l
G3v5KmT
public SiteInfoBean() >yDZw!C
{//nSplitter的缺省值为5 Y_P!B^z3
//default value of nSplitter is 5 |y!A&d=xYn
this("","","",5); ,/unhfs1q
} 7{Wny&[0
dAj$1Ke
Znv,9-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %&bY]w
{ 3Zh)]^
sSiteURL= sURL; lu/ (4ED
sFilePath = sPath; BJ(M2|VH
sFileName = sName; 08{@rOr
this.nSplitter = nSpiltter; Etm?'
w4Z'K&d=
#`s"WnP9'!
} poFg1
ybUaTD@?}b
e96k{C`j0
public String getSSiteURL() Rf1x`wml
{ akQ7K
return sSiteURL; }ad|g6i`
} [Vt\$
8dhUBJ0_
=vhm}
public void setSSiteURL(String value) <a+Z;>
{ |Q>IrT
sSiteURL = value; a'IdYW0
} ? =+WRjF
E_LN]v
teVM*-
public String getSFilePath() 4KrL{Z+}
{ dgePPhj
return sFilePath; T[A69O]v
} D1;QC
<9 ;!3xG
{l>hMxij
public void setSFilePath(String value) +nGAz{&@r%
{ Y6d@h? ht
sFilePath = value; qIqM{#' ^
} a.6(K
@=kSo -SX
as=LIw}Q4
public String getSFileName() `P ,d$H "
{ DlNX 3
return sFileName; |^H5^k "Bv
} ;*&-C9b
xkR0
GuL<Z1<c
public void setSFileName(String value) >F&47Yn
{ Sa5G.^XI
sFileName = value; )\^-2[;
} `@s^(hc7i
X\F|Tk3_
5/z/>D;
public int getNSplitter() X[TR3[1}
{ `y* }lg T
return nSplitter; t&DEb_"De
} Wo,?+I
29q _BR *:
~F7gP{r
public void setNSplitter(int nCount) iG?[<1~
{ dC4'{n|7
nSplitter = nCount; 4xJQ!>6
} >yh2Lri
} Y[S1$(K&*
>@AB<$A
RCLeA=/N@0
/* C{wEzM:
**Utility.java u>/ TE
*/ \5cpFj5%
package NetFox; }4S6Xe
;6hOx(>`=
2)~> R
public class Utility { 1@=po)Hnp
'[O;zJN;
uRe'%?W
public Utility() da~],MN
{ &G$Ucc `
KCDE{za
P L+sR3bR
} 1g~R/*Jo
R_xRp&5
//线程睡眠 /|#fejPh
public static void sleep(int nSecond) t);/'3|
{ Vs{|xG7WD
try{ G9vpt M
Thread.sleep(nSecond); G9@0@2aY8
} *k>n<p3dd
catch(Exception e) Q)z8PQl O
{ BDZ?Ez\Sg
e.printStackTrace (); xi;`ecqS<
} RY*U"G0#w
} 5i{j' {_(8
EDs\,f}
//日志 ,3 u}x,
public static void log(String sMsg) 5QO9Q]I#_\
{ e64^ChCoV
System.err.println(sMsg); Lq!>kT<]!
} ;P&OX5~V
Y:)e(c"A
B^jc3 VsR
public static void log(int sMsg) t@+}8^M
{ m<2M4u
System.err.println(sMsg); :S(ZzY Q
} R_S.tT!
} ?#Q #u|~
ib791
u,Kly<0j
/* S?BG_J6A7
**TestMethod.java 26x[X.C:
*/ 1 I",L&S1
package NetFox; Ef13Q]9|
&UlWCOo8
CQDkFQq-dq
public class TestMethod { 1hNq8*|
(0kK_k'T
@2v_pJy^
public TestMethod() =rX>1
{ ///xx/weblogic60b2_win.exe IRqy%@)
try{ d4z/5Oa
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )TM4R)r%)9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i8HTzv"J
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8Kk(8a&v
fileFetch.start(); DrK{}uM
} y Fq&8 x<X
catch(Exception e){e.printStackTrace ();} ;@E$}*3[>V
LvYB7<zk>
-!]ZMi9
} ?p8_AL'RS
J`1rJ
5rZ
public static void main(String[] args) t}tEvh
{ G?Hdq;
new TestMethod(); G9<X_
} /fV;^=:8c
} ?#UO./"
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