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)); He^+>XIam
} 1uz9zhG><
for(int i=0;i<nEndPos.length-1;i++) g #u1.|s&p
{ %h 6?/
nEndPos = nStartPos[i+1]; /ZHuT=j1
} p{xO+Nx1a
nEndPos[nEndPos.length-1] = nFileLength; ==`K$rM
} 1BwCJ7?8
} E9HA8
n?_!gqK
}legh:/*?O
//启动子线程 v' .:?9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )(TaVHJR
for(int i=0;i<nStartPos.length;i++) S9J<3 =
{ Brr{iBz*"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), > xkl7D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &}@U#w]l
nStartPos,nEndPos,i); Fx2 KRxk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f!a[+^RB:
fileSplitterFetch.start(); ;X-~C.7k
} qEPvV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), //]g78]=O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]]`hnzJX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hH[UIe
nEndPos = " + nFileLength); a_4Ny
// fileSplitterFetch[nPos.length-1].start(); 7)!(0.&
$UavM|
lrB@n?hk
//等待子线程结束 I8@NQ=UV0
//int count = 0; *Uie{^p?
//是否结束while循环 s$css{(ek
boolean breakWhile = false; fs+l
,$EM3
)(~4fA5j)
while(!bStop) T`7;Rl'Q
{ ne] |\]
write_nPos(); eU'DQp*
Utility.sleep(500); v]\io#
breakWhile = true; I1yZ7QY
>Lp^QP1gU
h!ZEZ|{
for(int i=0;i<nStartPos.length;i++) MKLntX
{ "- S2${
if(!fileSplitterFetch.bDownOver) e^Q$Tog<
{ e}yoy+9
breakWhile = false; YMOy6C
break; 3?SofPtc/
} eBX#^
} md:$OC3
if(breakWhile) Nl3x BM%
break; h\".TySz
x4fl=
Wm$(b2t
//count++; ,}2yxo;i
//if(count>4) <-62m8N|
// siteStop(); A]"$O&l
} 5!u.w
*t J+!1
J/S 47J~
System.err.println("文件下载结束！"); \9;u.&$mNB
} 0&T0Ls#4
catch(Exception e){e.printStackTrace ();} BoZ])Y6=
} s8Kf$E^?e.
Z3?,r[
qawb9Iud0
//获得文件长度 :=vB|Ch:~
public long getFileSize() #mwV66'H
{ w6DK&@w`'/
int nFileLength = -1; ',j'Hf
try{ >ch{u{i6
URL url = new URL(siteInfoBean.getSSiteURL()); w='1uV<6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wEL$QOu$
httpConnection.setRequestProperty("User-Agent","NetFox"); =S/$h}Vi
iL(rZT&^
6z v+Av:
int responseCode=httpConnection.getResponseCode(); g*C&Pr3
if(responseCode>=400) k%-_z}:3V
{ Gc2sY 0
processErrorCode(responseCode); le*mr0a
return -2; //-2 represent access is error ~l"70\&
} S6-)N(3|
wjh[}rTV*
%^s;{aN*!
String sHeader; ^ZnlWZ@r
TxAT ))
y;A<R[|Ve
for(int i=1;;i++) {N1Ss|6
{ OJ8ac6cJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jv7-i'I@
//Utility.log(in.readLine()); 4DI.RK9
sHeader=httpConnection.getHeaderFieldKey(i); JwWW w1
if(sHeader!=null) ?:l3O_U5
{ -y]\;pbZ0
if(sHeader.equals("Content-Length")) >m='#x0>Y
{ .,zrr&Po
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,JIjAm*2
break; cPA-EH
} )\!_`ob
} s\ft:a@
else RM\it"g
break; nIdB,
} USfpCRj9
} *0zdI<Oe
catch(IOException e){e.printStackTrace ();} `|K30hRp:
catch(Exception e){e.printStackTrace ();} Z$!>hiz2
[uCW8:e
ucP}( $
Utility.log(nFileLength); qN((Xz+AZE
WLGk
sv`+?hjG
return nFileLength; am,UUJ+h>
} ol]"r5#Q_H
Nd!0\ "AE
,E,oz{,i(
//保存下载信息（文件指针位置） WE\@ArY>
private void write_nPos() I;iJa@HWQ
{ U-/-aNJ]U
try{ |uo<<-\jTO
output = new DataOutputStream(new FileOutputStream(tmpFile)); fp!Ba
output.writeInt(nStartPos.length); <)n8lIK
for(int i=0;i<nStartPos.length;i++) cU <T;1VQ
{ EIZSV>
// output.writeLong(nPos); pvCn+y/U;
output.writeLong(fileSplitterFetch.nStartPos); y<r7_ysi
output.writeLong(fileSplitterFetch.nEndPos); P,5gaT)
} )>,; GVu"
output.close(); j2O?]M
} Yw7+wc8R
catch(IOException e){e.printStackTrace ();} 7A0D[?^xe
catch(Exception e){e.printStackTrace ();} R'RLF =
} gBM6{48GF
o.Ld.I)
R T/T+Q!
//读取保存的下载信息（文件指针位置） mqL&bmT
private void read_nPos() UeNa
{ cHN eiOF
try{ L ;5R*)t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u&MlWKCi
int nCount = input.readInt(); )Los\6PRn
nStartPos = new long[nCount]; xEv]VL:
nEndPos = new long[nCount]; &"!s+_
for(int i=0;i<nStartPos.length;i++) |eS5~0<`
{ 9WN4eC$
nStartPos = input.readLong(); AIZs^ `_
nEndPos = input.readLong(); vY|{CBGbd
} gG"W~O)yv
input.close(); d+FS
} :4 9ttJl
catch(IOException e){e.printStackTrace ();} Glz)-hjJ:n
catch(Exception e){e.printStackTrace ();} 2c?-_OCy;
} :N!Fe7H,
Rou$`<{H
D0T0Km/"
private void processErrorCode(int nErrorCode) kMD:~V
{ 1J$sIY,Ou
System.err.println("Error Code : " + nErrorCode); aH@Ux?-}
} ?^TjG)e7
|#<PI9)`
E,"?RbG
//停止文件下载 .&Uu w
public void siteStop() 32DT]{-N!
{ Y@)iPK@z
bStop = true; l| 1O9I0Gd
for(int i=0;i<nStartPos.length;i++) 8?ig/HSt2
fileSplitterFetch.splitterStop(); lPcp 17U
e[txJ*SuO
5AmYrXZ
} `-)!4oJ]
} !Jh/M^
//负责部分文件的抓取 u=a5Z4N'
**FileSplitterFetch.java Vc}#Ok
*/ \i Ylh HD
package NetFox; 0bY}<x(;
ex_Zw+n
H|a9};pO\
import java.io.*; /r Q4JoR>
import java.net.*; C"X; ,F<
HN7C+e4U~
/EW1&
public class FileSplitterFetch extends Thread { H Pvs~`>V
tCoT-\Q
"9>.,nzt
String sURL; //File URL aaa6R|>0
long nStartPos; //File Snippet Start Position j,:vK
long nEndPos; //File Snippet End Position m :M=De
int nThreadID; //Thread's ID x(r>iy
boolean bDownOver = false; //Downing is over 3rRN~$
boolean bStop = false; //Stop identical PG@Uygahu
FileAccessI fileAccessI = null; //File Access interface x'OYJ>l|
86_`Z$ s
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SuorCp]
{ 2.6F5&:($
this.sURL = sURL; ,lsoxl
this.nStartPos = nStart; @d/Wa=K
this.nEndPos = nEnd; Ug2^cgL
nThreadID = id; LBCat=d<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z_tK3kQa@&
} |;[%ZE"
RdtF5#\z
x9NcIa9
public void run() <691pkX
{ a#_=c>h;
while(nStartPos < nEndPos && !bStop) /Mg$t6vM
{ 9|}u"jJB%E
)T_o!/\*|*
H fg2]N
try{ SMMsXH
URL url = new URL(sURL); _`H2CXGg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }:b6WN;c
httpConnection.setRequestProperty("User-Agent","NetFox"); "RkbT O
String sProperty = "bytes="+nStartPos+"-"; {1<XOp#b
httpConnection.setRequestProperty("RANGE",sProperty); 5 aT>8@$Z^
Utility.log(sProperty); |UGmIm%
{Xc^-A[~
kvdiDo
InputStream input = httpConnection.getInputStream(); {x-iBg9#l2
//logResponseHead(httpConnection); o9j*Yz
gG 9e.++:
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byte[] b = new byte[1024]; J0 [^hH
int nRead; Nx%]dOa
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8Moe8X#3
{ ({R-JkW:;
nStartPos += fileAccessI.write(b,0,nRead); n%SR5+N"
//if(nThreadID == 1) o|tq&&! <
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d~G, *
} L7gZ4Hu=`
C9,|G7~*q
z ?3G`
Utility.log("Thread " + nThreadID + " is over!"); .IO_&^
bDownOver = true; !mM`+XH
//nPos = fileAccessI.write (b,0,nRead); \z~wm&
} 0ESxsba
catch(Exception e){e.printStackTrace ();} ];3]/b)&
} <wIz8V
} .nN>Ipv
j,]KidDWm
I3ZlKI
//打印回应的头信息 bv NXA*0
public void logResponseHead(HttpURLConnection con) \!+#9sq0
{ E`"<t:RzF
for(int i=1;;i++) G$eA(GE
{ 2"'<Yk9
String header=con.getHeaderFieldKey(i); cl`!A2F1G#
if(header!=null) pX\Y:hCug
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8zOoVO
Utility.log(header+" : "+con.getHeaderField(header)); ~6<'cun@x
else K5h2 ~
break; 2 SJN;A~}
} &=KNKE`
} R#n!1~ (
&|d6
$=IJ-_'o
public void splitterStop() 2b[R^O}
{ nx2iEXsa
bStop = true; B@8M2Pl
} G1X${x7
oB$P6
6]Vf`i
} eB]R<a60
9On0om>
60iMfcT
/* f4b`*KGf
**FileAccess.java RRasX;zK
*//文件访问(定位，写) h&k*i
package NetFox; 5Nt40)E}sN
import java.io.*; k)a3j{{
bW/^2B
;PA^.RB
public class FileAccessI implements Serializable{ odm!}stus
6>hW.aq}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 3SeM:OYq]s
RandomAccessFile oSavedFile; fx"~WeVcO
long nPos; wH<'*>/
W`d\A3v
kf Xg\6uKc
public FileAccessI() throws IOException }(yX$ 3?`
{ ^@4$O|3Wh'
this("",0); G<MX94?
} 8M_p'AR\,y
]E:P-xTwaI
1B5]1&M
public FileAccessI(String sName,long nPos) throws IOException 6]mFw{6qn1
{ JtB]EvpL}
oSavedFile = new RandomAccessFile(sName,"rw"); dB=aq34l
this.nPos = nPos; F.DRGi.i
oSavedFile.seek(nPos); 1pDL()t
} 5?yc*mOZ
`\]gNn'Q
VOa7qnh4:[
public synchronized int write(byte[] b,int nStart,int nLen) Ibbpy++d[
{ n;w&}g
int n = -1; 5TB==Fj ?
try{ #% 1|$V*:
oSavedFile.write(b,nStart,nLen); (TF;+FRW
n = nLen; f-'$tMs
} M#5*gWfq9
catch(IOException e) PAcbC|y
{ tnn,lWu|
e.printStackTrace (); >(9"D8
} -:P`Rln
,RYahu
Wb7z&vj
return n; G^6\OOSy
} f'-) 3T
q]}1/JZS
1f/8XxTB
} -|/kg7IO\
q_gsYb
"{X_[
/* %(v<aEQtt
**SiteInfoBean.java ]ICBNJ
*/ 4pw:O^v
package NetFox; 0D=7Mef
ZBf9Upg
!J%m7A
public class SiteInfoBean { AY~~a)V
#ozQF~
Fu/{*4
private String sSiteURL; //Site's URL 2TZ+R7B?
private String sFilePath; //Saved File's Path RO9oO7S
private String sFileName; //Saved File's Name Jemb0Qv
private int nSplitter; //Count of Splited Downloading File OD~TWT_
P?Fm<s:
h=`1sfz
public SiteInfoBean() 1$^=M[v
{//nSplitter的缺省值为5 A>OGU ^
//default value of nSplitter is 5 `& (Fy
this("","","",5); ]L?DV3N
} 320g!r
|:{H4
Z?o?"|o
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) r!,/~~mT
{ u}L;/1,B
sSiteURL= sURL; R2%>y5dD
sFilePath = sPath; %w0Vf$
sFileName = sName; B<A=U r
this.nSplitter = nSpiltter; 6?X)'
}K%y'D
9"TPAywd
} F]"Hs>
(XDK&]U
>FRJvZ6
public String getSSiteURL() FKN!*}3
{ ]F]!>dKA
return sSiteURL; n~wNee
} ZvS|a~jO
8UANB]@Y}
JnT1-=t.
public void setSSiteURL(String value) ,PyA$Z
{ pJK}9p=4`
sSiteURL = value; !83N. gN
} tUp'cG
xg>AW Q
'[6o(~*
public String getSFilePath() Zk4(
{ tl:+wp7P`
return sFilePath; J:c]z9&!
} hjgxCSp
Fk 5;
V=C@ocyZ
public void setSFilePath(String value) bLHj<AX#>|
{ 9b0M'x'W5
sFilePath = value; oo:(GfO}
} 5G-}'-R
VS:UVe
77Fpb?0`
public String getSFileName() .skR4f,h
{ zMXlLRC0
return sFileName; rX*ATN
} Jhyb{i8RR
&d`z|Gx9
4rh*&'
public void setSFileName(String value) /cy'% .!
{ 7sQw&yUL)
sFileName = value; Vo\RtM/6{
} [;Q8xvVZ'
kJJUu
G2nL#l~@)
public int getNSplitter() vlD!YNy
{ =!G3YZ
return nSplitter; M=!RJ%6f
} MBbycI,
bHr2LhQCN
Y]5\%JR
public void setNSplitter(int nCount) U[$KQEJYj
{ ">n38:?R
nSplitter = nCount; 5PJB<M_m:
} P~)ndaQ
} r~sx]=/
Y=oj0(Q*
)TceNH
/* T41&;?-
**Utility.java &AMW?vO
*/ qNhQ2x\
package NetFox; [mSK!Y@u
DRo@gYDn
$XqfwlUu/4
public class Utility { fb5]eec
yqF$J"=|
U}xQUFT|
public Utility() 8t$a8 PE
{ GfAt-huL(
3U&QonCV
^@ GE1
} Hp_3BulS<
;SzOa7
//线程睡眠 AW8"@
public static void sleep(int nSecond) `0rEV_$
{ "hU'o&
try{ _Cv({m&N
Thread.sleep(nSecond); BJ3st
} zh$[UdY6
catch(Exception e) Y8I$JBO
{ z.g'8#@
e.printStackTrace (); pa&*n=&cL
} |X9YVZC
} b|T}mn
k/vE|
//日志 =5EG}@
public static void log(String sMsg) =6t)-53
{ im^G{3z
System.err.println(sMsg); >JFAE5tj&2
} t_&FK A
o<e AZ
M:OY8=V
public static void log(int sMsg) *-bR~
{ 9hI4',(rE
System.err.println(sMsg); WKZ9i2hcdf
} @b2{'#9]}
} 6Flc4L8JU
b1>%%#
R|h9ilc
/* 3ug{1M3
**TestMethod.java 4YkH;!M>ji
*/ /4j'?hB<g
package NetFox; "])X0z yM
bL+Hw6;
yqqP7
public class TestMethod { 'DlY8rEGP
3|RfX
<tAn2e!
public TestMethod() \;p5Pagx0-
{ ///xx/weblogic60b2_win.exe 8ON$M=Ze$
try{ ]j0v.[SX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .l5y!?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IuTZ2~
SiteFileFetch fileFetch = new SiteFileFetch(bean); j& f-yc'i-
fileFetch.start(); "8VCXD
} l%lkDh!$"
catch(Exception e){e.printStackTrace ();} ,T_HE3K
Z~$=V:EA?
|UM':Ec
} L #p-AK
\uQB%yMoz
oddS~lW
public static void main(String[] args) 2t\a/QE)E
{ :*#AJV)
new TestMethod(); p+#J;.
} +60zJ4
} e2;19bj&
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