http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); H&M1>JtE
} a:85L!~:l
for(int i=0;i<nEndPos.length-1;i++) *HR+a#o
{ 9B /s
nEndPos = nStartPos[i+1]; {P-xCmZ~Wt
} $@_{p*q
nEndPos[nEndPos.length-1] = nFileLength; 93j{.0]X
} M\Se_
} a6%@d_A
bW53" `X
v?L
//启动子线程 [ `7%sn]$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3UdU"d[75
for(int i=0;i<nStartPos.length;i++) v:E;^$6Vn
{ Yu'a<5f
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L>dkrr)e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 74+A+SK[
nStartPos,nEndPos,i); (S`6Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zDD4m`2
fileSplitterFetch.start(); aX;A==>
} hk%k(^ekU]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hou*lCA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t8QRi!\=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F|>05>8
nEndPos = " + nFileLength); |( G2K'Ab
// fileSplitterFetch[nPos.length-1].start(); vA=Z=8
yGxv?%%2
(&jW}1D
//等待子线程结束 `H\)e%]
//int count = 0; v5_7r%Hiw
//是否结束while循环 "+)K |9T#
boolean breakWhile = false; OOnX`
g+xw$A ou
Ve}[XqdS^p
while(!bStop) wd[eJcQ,
{ ad9CsvW
write_nPos(); 4WC9US-k
Utility.sleep(500); C-m*?))go
breakWhile = true; `5q ;ssu
yEq#Dr
*^]~RhjB
for(int i=0;i<nStartPos.length;i++) Tzzq#z&F
{ Ytao"R/
if(!fileSplitterFetch.bDownOver) aBhV3Fd[B
{ !SO8O
breakWhile = false; b O=yi)
break; +L0w;wT
} zvY+R\,in
} MuwQZ]u
if(breakWhile) Ha%F"V*
break; 2?W7I/F
5rb-U7 /
9'nH2,_
//count++; )0k']g5
//if(count>4) n2{SV
// siteStop(); }s_hD`'
} [84F09HU
T-gk<V
g JjN<&,
System.err.println("文件下载结束！"); er2cQS7R
} x&Cp> +i
catch(Exception e){e.printStackTrace ();} .$&Q[r3Lu
} e4`uVq5
a^t?vv
H6K`\8/SeN
//获得文件长度 )}MHx`KT2
public long getFileSize() .$!{-v[
{ #]E(N~
int nFileLength = -1; ujr(K=E
try{ GaekFbW)
URL url = new URL(siteInfoBean.getSSiteURL()); y<- _(^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S QY"OBo<e
httpConnection.setRequestProperty("User-Agent","NetFox"); t P"\J(x
u,1}h L
+/rH(Ni
int responseCode=httpConnection.getResponseCode(); ,qQG;w,m
if(responseCode>=400) 3GH(wSv9\
{ k`\R+WK$
processErrorCode(responseCode); ]ikomCg
return -2; //-2 represent access is error -r<#rITH"
} 3QXjD/h
[q*%U4qGO
-.IEgggf
String sHeader; J~#$J&iKh
R"AUSO|{
52d^K0STC
for(int i=1;;i++) C[uOReo
{ kW@,$_cK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w%y\dIeI'
//Utility.log(in.readLine()); ?F7o!B
sHeader=httpConnection.getHeaderFieldKey(i); C/=XuKE-t
if(sHeader!=null) +GF#?X0^
{ 'zZcn" +!
if(sHeader.equals("Content-Length")) $w#r"= )
{ #!2k<Q*5uT
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G8Z4J7^
break; i3VW1~.8
} S'LZk9E
} )IL #>2n?
else .8WXC
break; ({^9<Us
} e>}}:Ud
} \HZ9S=
catch(IOException e){e.printStackTrace ();} "TcW4U9
catch(Exception e){e.printStackTrace ();} Ge+0-I6Ju
)$Mmn
B,WTHU[AV
Utility.log(nFileLength); BvD5SBa}"
tV;`fV
Y&HK1>M_
return nFileLength; o%E;3l
} uI~S=;o
N8r*dadDd
\x{;U#B[3>
//保存下载信息（文件指针位置） l_rn++
private void write_nPos() Z8#Gwyinx
{ S8d8%R~1=h
try{ 5kypMHJm
output = new DataOutputStream(new FileOutputStream(tmpFile)); nmU_N:Y
output.writeInt(nStartPos.length); Lw1EWN6}_&
for(int i=0;i<nStartPos.length;i++) .|qK+Hnc
{ h}`!(K^;3
// output.writeLong(nPos); JAjmrX
output.writeLong(fileSplitterFetch.nStartPos); 'XrRhF (
output.writeLong(fileSplitterFetch.nEndPos); 4+;$7"fJ
} :O<bA&:d
output.close(); x%+{VStA
} d[ >`")2)
catch(IOException e){e.printStackTrace ();} g*UMG>
catch(Exception e){e.printStackTrace ();} ;< jbLhHwD
} Yap?^&GV
G!N{NCq
RyJ 1mAC
//读取保存的下载信息（文件指针位置） )d\j I
private void read_nPos() (>4aibA'P
{ :~Q!SL N
try{ }R[#?ty;]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $?G"GQ!.
int nCount = input.readInt(); g>rp@M
nStartPos = new long[nCount]; l%ayI
nEndPos = new long[nCount]; oX@ya3!Pz
for(int i=0;i<nStartPos.length;i++) )tHaB,
{ 57a2^
nStartPos = input.readLong(); 'ly?P8h
nEndPos = input.readLong(); GQQ.OvEc
} 9>zcBG8f
input.close(); j$UV/tp5T
} 2aw&YZ&Xo
catch(IOException e){e.printStackTrace ();} #`TgZKDg2
catch(Exception e){e.printStackTrace ();} TGXa,A{
} B vo5-P6XY
~\)qi=
le+R16Z
private void processErrorCode(int nErrorCode) 0P^L}VVX
{ u]NZ`t%AP
System.err.println("Error Code : " + nErrorCode); =*qD4qYA
} &6 s) X
`@d<n
-oeL{9;
//停止文件下载 uwf 5!Z:>
public void siteStop() Hs?e0Z=N
{ E!BPE>
bStop = true; 7]xm2CHx5
for(int i=0;i<nStartPos.length;i++) ]M/9#mD9~
fileSplitterFetch.splitterStop(); RIu~ @
hz;|NW{u
Z/x*Y#0@n
} f<=Fsl
} ;*ix~taL%
//负责部分文件的抓取 9)xUA;Qw?z
**FileSplitterFetch.java )VL96did
*/ !Fo*e
package NetFox; Uoya3#4 G
[ EFMu;q
Djk C
import java.io.*; Uz cx6sw
import java.net.*; 2%*MW"Q
] Z8Vj7~
E$9Ys
public class FileSplitterFetch extends Thread { t?o,RN:
b|Q)[y]
QB.J,o*XD4
String sURL; //File URL 4'$g(+z
long nStartPos; //File Snippet Start Position )jWOP,|
long nEndPos; //File Snippet End Position 5aad$f
int nThreadID; //Thread's ID .=m,hu~
boolean bDownOver = false; //Downing is over x!\ONF5$
boolean bStop = false; //Stop identical +_XmlX A3Z
FileAccessI fileAccessI = null; //File Access interface l4n)#?Q?
H&r,FmI@
08X_}97#WF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j!7`]
{ y4h=Lki@
this.sURL = sURL; EbeI{-'aF
this.nStartPos = nStart; y\N|<+G+
this.nEndPos = nEnd; .@ xF6UZ
nThreadID = id; +("7ZK?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4Mk-2 Dx
} gaA<}Tp,
s9dO,FMs0t
i)#:qAtP*
public void run() m}>F<;hQ
{ DAo~8H
while(nStartPos < nEndPos && !bStop) iAT)VQ&
{ 8Ll[ fJZA
LIg{J%
Dnc(l(
try{ 1n%?@+W
URL url = new URL(sURL); .B#l5pfvP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3@5=+z~CW
httpConnection.setRequestProperty("User-Agent","NetFox"); %m:m}ziLQ
String sProperty = "bytes="+nStartPos+"-"; zlR?,h-[3
httpConnection.setRequestProperty("RANGE",sProperty); l5l>d62
Utility.log(sProperty); I`z@2Z+pJ
+T9:Udi
\!]Ua.e<
InputStream input = httpConnection.getInputStream(); BBcV9CGU
//logResponseHead(httpConnection); LZMYr
hhoEb(BA
f+rz|(6vs{
byte[] b = new byte[1024]; 4f(Kt,0
int nRead; 6}FO[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %OgS^_tu
{ Sq:0w
nStartPos += fileAccessI.write(b,0,nRead); FU=w(< R;
//if(nThreadID == 1) Ra*e5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kB5.(O
} NrP0Ep%V
GUslPnG
cb5,P~/q
Utility.log("Thread " + nThreadID + " is over!"); 2Z20E$Cb
bDownOver = true; 42>Ge>#F
//nPos = fileAccessI.write (b,0,nRead); Qt]Q:9I[
} e#/E~r&
catch(Exception e){e.printStackTrace ();} 8kP3+
} 1-.~7yC
} p4VeRJk%
zhY+x<-
*T0q|P~o%
//打印回应的头信息 @ 49nJi
public void logResponseHead(HttpURLConnection con) gm9mg*aM
{ r>GZ58i
for(int i=1;;i++) ?xK,mbFgl
{ Q f(p~a(d
String header=con.getHeaderFieldKey(i); =@F&o4)r
if(header!=null) r-,e;o>9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gWY"w!f
Utility.log(header+" : "+con.getHeaderField(header)); m7T)m0
else h*ZC*eV>
break; #07gd#j4
} :!zl^J;
} &@ JvnO:
(knp#
9'hv%A:\3
public void splitterStop() };'\~g,1
{ nC{%quwh{
bStop = true; *.)tG
} 9W5onn
wcDRH)AW.
!bV5Sr^
} ]({~,8s
qC'{;ko
VY)s+Bx
/* 2Pc%fuC
**FileAccess.java .$@R{>%U
*//文件访问(定位，写) 86 W0rS[5
package NetFox; Ecs,$\
import java.io.*; %v2R.?F8
H(Eh c
h<~7"ONhV
public class FileAccessI implements Serializable{ aZbw]0q@o
l3 DYg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1#1 riM -
RandomAccessFile oSavedFile; u+{a8=
long nPos; i1RiGS
3P;>XGCxZ
sUPz/Z.h
public FileAccessI() throws IOException @?"h !fyu
{ KN-avu_Ix
this("",0); mS0udHod
} }`+B=h-dW
``E/m<r:$
}<'5 z qS
public FileAccessI(String sName,long nPos) throws IOException Ks}Xgc\
{ %\i9p]=
oSavedFile = new RandomAccessFile(sName,"rw"); &IlU|4`R%
this.nPos = nPos; /> 4"~q)
oSavedFile.seek(nPos); Zdn~`Q{
} @O[5M2|r
N]RZbzK_5G
=Fdg/X1
public synchronized int write(byte[] b,int nStart,int nLen) ]5%/3P,/
{ }- Wa`t7U
int n = -1; "*})3['n
try{ ;t+ub8
oSavedFile.write(b,nStart,nLen); jbR0%X2
n = nLen; E\C9|1)
} K(q-?n`<
catch(IOException e) [k-+AA>:
{ >$2V%};
e.printStackTrace (); "le>_Ze_>|
} p0pWzwTG3
?mlNL/:
*_?dVhxf
return n; +T8B:
} uw2hMt (N
D.mHIsX6\
/JT#^Y
} a.z;t8
/q5:p`4{J
IUwm}9Q!
/* S%`0'lzzj
**SiteInfoBean.java (T2m"Yi:
*/ XQS9,Hl
package NetFox; Zv#Ll@v
!A%<#Gjt
rylzcN9RM$
public class SiteInfoBean { M}!2H*
PiA0]>
Q~T$N
private String sSiteURL; //Site's URL {P*m;a`}
private String sFilePath; //Saved File's Path KIWe@e
private String sFileName; //Saved File's Name xNbPsoK
private int nSplitter; //Count of Splited Downloading File yiO.z
F8apH{&t
50={%R
public SiteInfoBean() |DsnNk0c
{//nSplitter的缺省值为5 xt*u4%
//default value of nSplitter is 5 ~*wk6&|
this("","","",5); {D=@n4JO
} f;b[w
,N0#!<}4
H*)NLp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +>PX&F
{ 6:~v4W!k
sSiteURL= sURL; )P+7PhE{J
sFilePath = sPath; SCz318n
sFileName = sName; %VnbmoO
this.nSplitter = nSpiltter; /bVoErf
Gn&4V}F
!@v7Zu43,
} @mfEKU!
ynrT a..
^U!0-y
public String getSSiteURL() Er{>p|n=
{ yNTK .
return sSiteURL; ej"+:."\e
} hq #?kN
\o^2y.q:>
j*vYBGD
public void setSSiteURL(String value) #Q /Arq
{ =y-@AU8
sSiteURL = value; $b mLu=9
} a0#J9O_
(I./ Uu%
1.6:#
public String getSFilePath() .;N1N^
{ (UxW;
return sFilePath; _FWBUZ;N
} <Sr
[)TRTxFb
bR)(H%I
public void setSFilePath(String value) 9_5ow
{ ^RI?ybDd
sFilePath = value; :n-]>Q>5=k
} s']Bx=
PGoh1Uu
.~7FyLl$
public String getSFileName() @8I4[TE
{ _+E5T*dk
return sFileName; {Sj9%2'M)
} H|HYo\@F#
VB*oGG
XSyHk"g`
public void setSFileName(String value) |0f>aZ
{ r<d_[?1N
sFileName = value; 4.5|2\[
} gK'1ZLdZ2
OD!& .%
<d$x.in
public int getNSplitter() JVSA&c%3
{ ybKWOp:O
return nSplitter; )`(p9@,V
} #$8% w
XLrwxj0
}*S `qW;B
public void setNSplitter(int nCount) yvO{:B8%
{ |M,iM]
nSplitter = nCount; m0a?LY
} (bH`x]h#
} gq'Y!BBQy
z)r=+ -
E;R n`oxk
/* '$ t
**Utility.java I!Z_[M
*/ lrIjJ V
package NetFox; 7%|~>
J`].:IOh
oUQ,61H
public class Utility { ^Xq 6:
TI,&!E?;
FwkuC09tI
public Utility() HOJs[mqB%
{ (Fhs"
WGZ9B^A
jYmR
} SPY|K
Ssou
//线程睡眠 dQA'($
public static void sleep(int nSecond) UMm!B`M
{ biU^[g("
try{ -7@/[9Gf`:
Thread.sleep(nSecond); ij(B,Y
} TU,s*D&e
catch(Exception e) m!tbkZHQn0
{ Enn"hdI
e.printStackTrace (); 1;Cyz)
} LcTt)rs f
} D"2&P^-
BMG3|N^
//日志 xg;+<iW
public static void log(String sMsg) _4U5
{ ?kH8Lw~{5W
System.err.println(sMsg); Z8@J`0x
} xRzFlay8
1q:2\d]
Tz8PSk1[
public static void log(int sMsg) v50bdj9}k
{ #mCL) [
System.err.println(sMsg); iXVe.n
} 1AM!8VR2
} $!-c-0ub
R6kD=JY/!
J\:R|KaP<p
/* 7WkB>cn
**TestMethod.java ,*&:2o_r
*/ _u5#v0Y
package NetFox; $0>60<J
>_-s8t=|
zuJ@E=7
public class TestMethod { KWowN;
e478U$
G\Cp7:j}
public TestMethod() vgH3<pDiU6
{ ///xx/weblogic60b2_win.exe t\~P:"
try{ |y!=J$$_H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~=6xyc/c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j<VFn~*_
SiteFileFetch fileFetch = new SiteFileFetch(bean); e.7EU
fileFetch.start(); m.# VYN`+A
} p.v0D:@&
catch(Exception e){e.printStackTrace ();} QkEvw<
8*#R]9
s%nUaWp~
} S1Wj8P-
*`ua'"="k
n22zq6m
public static void main(String[] args) ~J wb`g.
{ RKHyw08
new TestMethod(); !;Yg/'vD-
} cl=EA6P\X
} aQ?/%\>
点击下载更多相关资料