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)); x ul]m*Z
} &`fhEN
for(int i=0;i<nEndPos.length-1;i++) Z*])6=2Q
{ ?_ dIIQ
nEndPos = nStartPos[i+1]; |=EZ1<KzD
} H<QT3RF2
nEndPos[nEndPos.length-1] = nFileLength; RGK8'i/X
} @]![o %
} o}<4*qlI
|,aG%MTL
5bA)j!#)|X
//启动子线程 efD)S92
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YFTjPBV
for(int i=0;i<nStartPos.length;i++) e#B#B
{ %eJGte-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0jzbG]pc:E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Raw)9tUt
nStartPos,nEndPos,i); .-JCwnP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m~>Y{F2
fileSplitterFetch.start(); '*Almv{
} /RyR>G!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <&!v1yR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jr)7kP@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {<5ybbhLV
nEndPos = " + nFileLength); HBY.DCN[Z
// fileSplitterFetch[nPos.length-1].start(); IJJ%$%F/
f"(X(1F
Hk7q{`:N
//等待子线程结束 8v71e>
//int count = 0; (4@lKKiU%H
//是否结束while循环 fi+R2p~vs
boolean breakWhile = false; NWd<+-pC6
XUF\r]B,9
0[F:'_
while(!bStop) /1 RAAa
{ 1RKW2RCaW_
write_nPos(); TyKWy0x-3
Utility.sleep(500); k6kM'e3V
breakWhile = true; cv(PP-'\
@w>zF/
yi^b)2G
for(int i=0;i<nStartPos.length;i++) i%{3W:!4t
{ 0A:n0[V:]
if(!fileSplitterFetch.bDownOver) @vMA=v7a
{ 1.D-FPK
breakWhile = false; ~Xlrvb}LP
break; !;Jmg
} hb/]8mR
} xcJ`1*1N
if(breakWhile) DOz\n|8S
break; m>}8'N)
{}o>{&X
O,<IGO
//count++; yIb,,!y9{
//if(count>4) cV-1?h63
// siteStop(); X1tXqHJF}
} !vn1v)6
7n o5b] \
WU4UZpz
System.err.println("文件下载结束！"); n}mR~YqD
} + <c^=&7Lq
catch(Exception e){e.printStackTrace ();} Wy]^Ub gW
} K\^ 0_F K
7DKz;o
6r"u$i`o
//获得文件长度 =V97;kq+v
public long getFileSize() 1ZJQs6
{ |BZDhd9<{
int nFileLength = -1; D^U: ih
try{ z^nvMTC
URL url = new URL(siteInfoBean.getSSiteURL()); Gq#~vr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `d2,*KR
httpConnection.setRequestProperty("User-Agent","NetFox"); f&4,?E;6%
@mt0kV9
OTB$V k
int responseCode=httpConnection.getResponseCode(); a4gi,pz$]
if(responseCode>=400) K~RoUE<3[
{ }]UB;id'
processErrorCode(responseCode); L?Yoh<
return -2; //-2 represent access is error YYg)
} k#}g,0@
1\L[i];L8
nsb4S{
String sHeader; *FR$vLGn
O;[9_[
wzjU,Mwe
for(int i=1;;i++) W2-=U@
{ Xl |1YX1&m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); he+#Q6
//Utility.log(in.readLine()); G+*cpn
sHeader=httpConnection.getHeaderFieldKey(i); :`vP}I ^
if(sHeader!=null) 9H]_4?aX
{ w(nHD*nm
if(sHeader.equals("Content-Length")) ]>i~6!@
{ fR-C0"c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,}D}oo*
break; n uQM^2
} nL]^$J$
} 4\ /*jA
else 1+y"i<3)
break; ^]p
} M~6@20$oW
} FZpKFsPx
catch(IOException e){e.printStackTrace ();} io4A>>W==/
catch(Exception e){e.printStackTrace ();} PWgDFL?
VY 1vXM3y
>x:EJV
Utility.log(nFileLength); (3,.3)%`
j%Y\A~DV
P}3}ek1Ax
return nFileLength; YJ7V`Np
} MN= sIP,zk
ET^|z
f%qt)Ick
//保存下载信息（文件指针位置） @=]8^?$t 0
private void write_nPos() X}4}&
{ 1@sM1WMX
try{ u~ F;xQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); {GqXP0'
output.writeInt(nStartPos.length); w3*-^: ?j
for(int i=0;i<nStartPos.length;i++) `kBnSio~
{ |@VF.)_
// output.writeLong(nPos); @y~P&HUN
output.writeLong(fileSplitterFetch.nStartPos); \Xg?Ug*9w
output.writeLong(fileSplitterFetch.nEndPos); *8g<R
} 2C+(":=}
output.close(); [!*xO?yCJ
} M7y|EB))
catch(IOException e){e.printStackTrace ();} {0jIY
catch(Exception e){e.printStackTrace ();} h%#_~IA:|
} 8LM#WIm?
zDBD.5R;
]= x 1`j
//读取保存的下载信息（文件指针位置） Aa(<L$e!`
private void read_nPos() @6xGJ,s
{ &&RA4
try{ DR+,Y2!_GT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,=w!vO5s
int nCount = input.readInt(); {/M\Q@j
nStartPos = new long[nCount]; }#N]0I)JI
nEndPos = new long[nCount]; 9fVj 8G
for(int i=0;i<nStartPos.length;i++) }~enEZ
{ oFg'wAO.
nStartPos = input.readLong(); R ZcH+?7
nEndPos = input.readLong(); 0g(6r-2)7
} =&NOHT>
input.close(); H*U`
} |+ 7f2C
catch(IOException e){e.printStackTrace ();} !;}2F-
catch(Exception e){e.printStackTrace ();} F,Fo}YQX
} 6&!l'[hU
a?<?5
5j[#'3TSU
private void processErrorCode(int nErrorCode) m4**>!I
{ LcUlc)YH5
System.err.println("Error Code : " + nErrorCode); {OxWcK\2@h
} E[S':Q
}$)&{d G
]tVl{" .{
//停止文件下载 _nX%#/{
public void siteStop() h(:<(o@<
{ (Pz8iz
bStop = true; F3 f@9@b
for(int i=0;i<nStartPos.length;i++) "a(1s},
fileSplitterFetch.splitterStop(); $N\+,?
wu^q`!ml
F.KrZ3%4iB
} %Dyh:h
} lP0k:
//负责部分文件的抓取 -Cj_B\
**FileSplitterFetch.java UH40~LxIma
*/ ^![{,o@"A
package NetFox; b>=7B6 Aw
9v?V
f'_S1\
import java.io.*; wznn #j
import java.net.*; FE6C6dW{
zz3 r<?#5
hZF(/4Z2
public class FileSplitterFetch extends Thread { |BJqy/
SKxe3
h]}`@M"
String sURL; //File URL q!2<=:f
long nStartPos; //File Snippet Start Position YX `%A6
long nEndPos; //File Snippet End Position 8nu> gA
int nThreadID; //Thread's ID |uQ[W17^N
boolean bDownOver = false; //Downing is over 5&%fkZ0
boolean bStop = false; //Stop identical sX~45u \
FileAccessI fileAccessI = null; //File Access interface 9Z9l:}bO
Ld~4nc$H8
yM17H\=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i@{*O@m
{ `r.N
this.sURL = sURL; 7kM4Ei
this.nStartPos = nStart; u9@b<
this.nEndPos = nEnd; y*|L:!
nThreadID = id; {e6KJ@H6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @ay|]w
} $O]^Xm3{@
<[5#c*A
-#Jj-t_Fe
public void run() MBv/
{ 5%qH7[dx
while(nStartPos < nEndPos && !bStop) aZxO/b^j
{ f@*>P_t
rBD2Si=
*s36OF!
try{ b\M b*o
URL url = new URL(sURL); .J:;_4x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |Ib.)
httpConnection.setRequestProperty("User-Agent","NetFox"); ,N;v~D$Y
String sProperty = "bytes="+nStartPos+"-"; :'ihE\j
httpConnection.setRequestProperty("RANGE",sProperty); T8mY#^sW_
Utility.log(sProperty); /[L)tj7B
@dl<-
e9}8RHy1$
InputStream input = httpConnection.getInputStream(); XP4jZCt9
//logResponseHead(httpConnection); VB's
E6JV}`hSk
d{l{P]nr
byte[] b = new byte[1024]; ,-!2 5G
int nRead; )ZeLaaP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $BaK'7=3*
{ T#Fn:6_=
nStartPos += fileAccessI.write(b,0,nRead); vQcUaPm\$
//if(nThreadID == 1) ~Q_F~0y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e %&
} uh1S 7!^
e-jw^
h%/ssB
Utility.log("Thread " + nThreadID + " is over!"); 0+p 5/5
bDownOver = true; BZ}`4W'
//nPos = fileAccessI.write (b,0,nRead); +L n M\n
} M-vC>u3Y
catch(Exception e){e.printStackTrace ();} gDMAc/V`l
} +!G4tA$g
} `{%-*f^
3 ^pYCK%
nc-Qz
//打印回应的头信息 !4_!J (q%
public void logResponseHead(HttpURLConnection con) *qbRP"#[$
{ XS3{R
for(int i=1;;i++) GIK u
{ T4vogoy
String header=con.getHeaderFieldKey(i); > Z]P]e
if(header!=null) va@XbUC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z%KL[R}^w;
Utility.log(header+" : "+con.getHeaderField(header)); /^~p~HKtx
else pAMo XJ`
break; '}@e5^oL
} :82?'aR
} &bn*p.=G
P`z7@9*j
h<GyplG
public void splitterStop() G]at{(^Vz
{ "Jf4N
bStop = true; k"0%' Y
} QXsfp
ys/`{:w8p
rtcJ=`)0`
} j1W bD7*8
gYRqqV
!B0v<+;P8
/* >y&[BB7S6
**FileAccess.java 4(m/D>6:
*//文件访问(定位，写) w4NZt|>5j;
package NetFox; $#F;xys
import java.io.*; N'I?fWN!;R
b8eDD+ulk
hT\p)w
public class FileAccessI implements Serializable{ <.;@ksCPW{
3D{82*&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ml'bZLwq
RandomAccessFile oSavedFile; GU2]/\W*a
long nPos; i:MlD5 F
5T7_[{
B8`R(vu;
public FileAccessI() throws IOException e6Wl7&@6
{ X*_ SHt
this("",0); yjeqv-7
} B9%yd*SJ
]kyle3#-~
Bidqf7v
public FileAccessI(String sName,long nPos) throws IOException s4^[3|Zrr0
{ f<Va<TL6-
oSavedFile = new RandomAccessFile(sName,"rw"); T^rz!k{
this.nPos = nPos; W ]a7&S
oSavedFile.seek(nPos); ]|H]9mys98
} .;]YJy
kxcgOjrmI
b>GqNf!
public synchronized int write(byte[] b,int nStart,int nLen) dw|-=~
{ dY/|/eOt<K
int n = -1; |:!EHFr
try{ JrY"J]/
oSavedFile.write(b,nStart,nLen); ,ivWVsN*]
n = nLen; ]9bh+
} " 8~f
catch(IOException e) 8 /:X& &
{ |6\FI?
e.printStackTrace (); 7vB9K_wCI
} 6$xo# }8
>FK)p
3C E 39W
return n; S jC)6mo
} 4WBoZJ
a!s.850@
GQEIf$
} ?yK%]1O
fRca"vV
_47j9m]f
/* 4GmSG,]
**SiteInfoBean.java -f-O2G=
*/ EhmUX@k],
package NetFox; >"PqQO
S)Ub/`f{s
N,'[:{GOY
public class SiteInfoBean { 0jip::x
ifgr<QlG
6Zl.Lh
private String sSiteURL; //Site's URL < e7<t9
private String sFilePath; //Saved File's Path $?CBX27AV
private String sFileName; //Saved File's Name ve6N
private int nSplitter; //Count of Splited Downloading File lEVQA*u[
8Izn'>"
4EaSg#
public SiteInfoBean() I8pv:>EhC
{//nSplitter的缺省值为5 3.K{T
//default value of nSplitter is 5 YiY&;)w
this("","","",5); d~P<M3#>
} ~%8Q75tn.
x):k#cu[L
?-RoqF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~|0F?~eR7
{ #buV;!_!E?
sSiteURL= sURL; h1G*y
sFilePath = sPath; TCEXa?,L
sFileName = sName; {8*d;[X50
this.nSplitter = nSpiltter; _taHf %\4
Tvksf!ba
1b %T_a
} e!2%ku
mV! @oNCK
\h'E5LO
public String getSSiteURL() XeIUdg4>R
{ 6|"!sW`%N
return sSiteURL; :+?W
} Gn2bZ%l
G2[IO $
i?i7T`
public void setSSiteURL(String value) P(YG@
{ "JQt#[9l
sSiteURL = value; zvK5Zxl
} x(/@Pt2B
;ow~vO,x
,SE$Rh
public String getSFilePath() =p&'_a^$
{ 6Qzu-
return sFilePath; D-b2E6o6
} "o5gQTwb
l:5CM[mZ
y T1Qep
public void setSFilePath(String value) @7[.>I(
{ _c(C;s3o
sFilePath = value; ah!O&ECh
} 4W//Oc@e
u6S0t?Udap
$bi_i|?
public String getSFileName() rJc)<OZjT
{ fO|~Oz<S
return sFileName; mJDKxgGK
} cf[u%{ 6Y
("JV:u.L+
"aCb;2Rs
public void setSFileName(String value) a+>W
{ t+4Y3*WeGF
sFileName = value; %[\Ft
} Wru Fp
gHh.|PysW
:!iPn%
public int getNSplitter() :2UC{_
{ kj3o1Y
return nSplitter; =[)N6XV3
} g<T`F
8$<AxNR
dj'8x48H2W
public void setNSplitter(int nCount) j_a~)o-p
{ | 8L`osg
nSplitter = nCount; C"Y]W-Mgg
} #!d^3iB2
} 548[!p4
]20"la5
">vYEkZ3
/* ,8"[ /@
**Utility.java (8-lDoW
*/ =@jMx^A"
package NetFox; aEqI51I
97))'gC
t|U2ws#
public class Utility { gUszMhHX
j.'"CU
&<P^Tvqq&
public Utility() cV_IG}LJ
{ -z 5k4Y
nM.?Q}yO~
Oc/_T>
} b;{"lJ:+Z
hHl-;%#
//线程睡眠 ocuVDC
public static void sleep(int nSecond) BfE-s<
{ 'GzhZ`E6
try{ aCi^^}!
Thread.sleep(nSecond); 73z|'0.
} AB&wn>q
catch(Exception e) u r.T YKF
{ n`T[eb~
e.printStackTrace (); .f<VmUca
} .yfqS|(
} YG1`%,OW`
'-]BSU
//日志 Y$$?8xr ~
public static void log(String sMsg) $0S"Lh{
{ n25tr'=
System.err.println(sMsg); ,Ho.O7H
} KIBZQ.uG
5F sj_wFk
o4 g
public static void log(int sMsg) kmr 4cU5
{ "gikX/Co=
System.err.println(sMsg); >Wit"p
} ~5!TV,>ls
} G1^!ej
jzA8f+:q
y'O{8Q8T
/* MHyl=5
**TestMethod.java rHBjR_L.2
*/ [5eT|uy
package NetFox; RrpFi'R
kBT}Siw
Y4qyy\}
public class TestMethod { :aqskeT
UR2)e{RXg
*#^1rKGWK
public TestMethod() HgATH
{ ///xx/weblogic60b2_win.exe !gew;Jz
try{ 6Oba}`)q9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h}&IlDG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D=sc41]
SiteFileFetch fileFetch = new SiteFileFetch(bean); _";pk _
fileFetch.start(); }~'Wz*Gm
} rPpAg
catch(Exception e){e.printStackTrace ();} ~%:p_td
O:p649A
KmOa^vY1.T
} be%*0lr
*`.{K12T
tRBK1h
public static void main(String[] args) FF!g9>
{ E(LE*J
new TestMethod(); K/+C6Y?
} hBE>ea
} iPO S
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