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)); @vMA=v7a
} kqb0>rYa
for(int i=0;i<nEndPos.length-1;i++) 9 C{;h
{ 4G@nZn
nEndPos = nStartPos[i+1]; \j2;4O?`
} hb/]8mR
nEndPos[nEndPos.length-1] = nFileLength; [I:KpAd/
} y}v+c%d
} &vovA} F
HK)cKzG[s!
{T'GQz+R"
//启动子线程 KI]wm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yIb,,!y9{
for(int i=0;i<nStartPos.length;i++) \]9.zlB
{ @R m-CWa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D{v8q)5r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `p'Q7m2y/b
nStartPos,nEndPos,i); 7n o5b] \
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XM<KF&pVB
fileSplitterFetch.start(); x"4} isp<
} ez3Z3t`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ke-)vPc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kGkA:g:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y:ldR
nEndPos = " + nFileLength); `imWc"'Ej
// fileSplitterFetch[nPos.length-1].start(); a{[+<8=@1
.P$IJUYO
I5AO?BzJ
//等待子线程结束 T<-=nX
//int count = 0; ?4CNkk=v
//是否结束while循环 Cv)/7vyB8
boolean breakWhile = false; (]*H[)F/
z^nvMTC
NA$zd(
while(!bStop) 0lM{l?
{ jxgj,h"}9`
write_nPos(); 8wH.et25k
Utility.sleep(500); NDO\B,7
breakWhile = true; K1?Gmue#I
-S%x wJKM
<P%}|@
for(int i=0;i<nStartPos.length;i++) '<iK*[NW
{ qEUT90
if(!fileSplitterFetch.bDownOver) ._z'g_c(
{ QMo}W{D
breakWhile = false; qW_u
break; Q>qFM9Z
} CJaKnz
} 3ew8m}A{O
if(breakWhile) fU2qrcVu
break; +]:2\TTGI
*FR$vLGn
RQW6N??C
//count++; 5~XN>>hp
//if(count>4) W2-=U@
// siteStop(); gLE7Edcp6V
} _U|7'^|
Xj+q~4{|vt
=\, qP
System.err.println("文件下载结束！"); KyP)Qzp
} %m{U& -(l@
catch(Exception e){e.printStackTrace ();} kJs^ z
} 5wC* ?>/
]>i~6!@
lo&#(L+2
//获得文件长度 W&"|}Pi/
public long getFileSize() .wrL3z_
{ n uQM^2
int nFileLength = -1; :Zw@yt
try{ !SHj$Jwa'
URL url = new URL(siteInfoBean.getSSiteURL()); 7@%'wy&A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _L.n,
httpConnection.setRequestProperty("User-Agent","NetFox"); % 0:p)Z0
vOI[Z0Lq9h
-m 5}#P89
int responseCode=httpConnection.getResponseCode(); RAs0]K
if(responseCode>=400) C.!_]Pxs
{ ALd;$fd qf
processErrorCode(responseCode); \'?#i@O
return -2; //-2 represent access is error oh#N 0 0X
} >x:EJV
fvo<(c#Y#
fn{S "33"
String sHeader; J?:[$C5
)wzV $(~
7q9gngT1LA
for(int i=1;;i++) !{_yaVF
{ x;BbTBc>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9vGs;
//Utility.log(in.readLine()); f%qt)Ick
sHeader=httpConnection.getHeaderFieldKey(i); HO|-@yOF^
if(sHeader!=null) xcCl (M]+
{ |E/L.gdP7
if(sHeader.equals("Content-Length")) 7_KhV
{ (d2@Mz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); q$ghLGz
break; r@)A k
} zz$q5[n
} &;q<M_<
else NSLVD[yT
break; v$|mo;6
} \94jrr
} J>S3sP
catch(IOException e){e.printStackTrace ();} %.x@gi q
catch(Exception e){e.printStackTrace ();} h!]"R<QQdu
X.|Ygx
v1[_}N9f>H
Utility.log(nFileLength); 3-wD^4)O,
{0jIY
d}0qJoH4
return nFileLength; &y_? rH
} V/#v\*JHFc
\ a-CN>
Fq,N
//保存下载信息（文件指针位置） o#i ]"
private void write_nPos() nf%4sIQ*x
{ |DG@ht
try{ +/'<z
output = new DataOutputStream(new FileOutputStream(tmpFile)); )q?$p9
output.writeInt(nStartPos.length); z)L}ECZh9
for(int i=0;i<nStartPos.length;i++) Q2'eQ0W{o
{ M StX*Zw
// output.writeLong(nPos); 7|D|4!i2Y
output.writeLong(fileSplitterFetch.nStartPos); L-'k7?%(
output.writeLong(fileSplitterFetch.nEndPos); sB*o)8
} MR9/Y:Nm
output.close(); D,W\ gP/h%
} hFb fNB3
catch(IOException e){e.printStackTrace ();} w{7ji}
catch(Exception e){e.printStackTrace ();} )@PnTpL*
} m3 IP7h'
!QC<n/
;lfWuU%R
//读取保存的下载信息（文件指针位置） 0o/B{|rv
private void read_nPos() |+ 7f2C
{ Q)6va}2ai
try{ #Q6w+"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =Lw3 \5l
int nCount = input.readInt(); 3XVk#)lw
nStartPos = new long[nCount]; I"Q<n[g0'
nEndPos = new long[nCount]; ua& @GXvZ
for(int i=0;i<nStartPos.length;i++) z%2w(&1
{ Kmry=`=A
nStartPos = input.readLong(); !]DuZ=
nEndPos = input.readLong(); )bW<8f2
} X=_Z(;<&
input.close(); kO3`54
} H@!#;w
catch(IOException e){e.printStackTrace ();} D9,! %7i
catch(Exception e){e.printStackTrace ();} &:vscOl
} )A83A<~
#MM&BC
IRB& j%LA
private void processErrorCode(int nErrorCode) %-^}45](q
{ g,?\~8-c
System.err.println("Error Code : " + nErrorCode); *wUdC
} @l,{x|00
_g6wQdxT
|zMqJ.qu
//停止文件下载 Y+|PY? ~
public void siteStop() 0BC`iql5
{ Mvof%I
bStop = true; NWISS
for(int i=0;i<nStartPos.length;i++) 6&],WGz
fileSplitterFetch.splitterStop(); 9s $PrF
KM5 JZZP
ec'tFL#u{
} 9.8,q
} DT? m/*
//负责部分文件的抓取 F$ {4X /9n
**FileSplitterFetch.java SI_?~Pf3k
*/ 7\/u&
package NetFox; I@PJl
,8`O7V{W
#:W%,$9\P
import java.io.*; A}4t9|/K6
import java.net.*; C"No5r'K3
+!$dO'0nt,
:@e\'~7sH
public class FileSplitterFetch extends Thread { %c0z)R~
2?1}ZXr
22IYrk
String sURL; //File URL %MNk4UsV
long nStartPos; //File Snippet Start Position ^Jtl;Q
long nEndPos; //File Snippet End Position "`]'ZIx[R/
int nThreadID; //Thread's ID PN9^[X
boolean bDownOver = false; //Downing is over Ut;'Gk
boolean bStop = false; //Stop identical z@`@I
FileAccessI fileAccessI = null; //File Access interface U$09p;~$Ww
>Fh#DmQ
x vJ^@w'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5ZUy:
{ >W~=]&7{s4
this.sURL = sURL; J" wKRy
this.nStartPos = nStart; {e6KJ@H6
this.nEndPos = nEnd; &G=0
nThreadID = id; =BW9/fG
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dqwWfn1lt
} iE+6UK
u2,H ]-
E@]sq A
public void run() (olLB
{ TPqvp|~2
while(nStartPos < nEndPos && !bStop) pg5&=
{ r4S=I
k) 3s?
\d$Rd")w
try{ f~v"zT
URL url = new URL(sURL); b\M b*o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a'^0.1
httpConnection.setRequestProperty("User-Agent","NetFox"); |P~q/Wff
String sProperty = "bytes="+nStartPos+"-"; u!u5g.Q
httpConnection.setRequestProperty("RANGE",sProperty); _M&{^d
Utility.log(sProperty); h;}ODK(.
}(cY|
l}+Cdy9>
InputStream input = httpConnection.getInputStream(); 5])8qb/F
//logResponseHead(httpConnection); *sAOpf@M
ytob/tc
'M lXnHxt
byte[] b = new byte[1024]; k?n]ZNlT
int nRead; #O><A&FrF`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s%bUgO%&
{ U~hCn+0
nStartPos += fileAccessI.write(b,0,nRead); pNSst_!>
//if(nThreadID == 1) L3g9b53\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V:QdQ;c
} ?AT(S
A_]D~HH
y* rY~U#3
Utility.log("Thread " + nThreadID + " is over!"); TL]bY'%
bDownOver = true; Bf+^O)Ns^
//nPos = fileAccessI.write (b,0,nRead); YjL t&D:IZ
} W`5a:"Vg
catch(Exception e){e.printStackTrace ();} [Q=4P*G}X
} m"q/,}DR
} }eI`Qg
CCn/ udp@
e-jw^
//打印回应的头信息 " C&x,Ic
public void logResponseHead(HttpURLConnection con) IF^[^^v+H
{ xLZMpP5c
for(int i=1;;i++) @,GjeF]!
{ .2/,XwIr
String header=con.getHeaderFieldKey(i); QWQ!Ak
if(header!=null) WySNL#>a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4xpj<
Utility.log(header+" : "+con.getHeaderField(header)); G6<HO7\
else J/= +r0c
break; q1P :^<[
} =J`gGDhGY-
} >Rr!rtc'x
qZ233pc
vD_u[j]
public void splitterStop() {q})kO
{ i5Eeg`NMl
bStop = true; F],TG&>5
} _J` |<}?t;
> Z]P]e
#*+;B93)
} 7 s7}?l9
,R8n,az
x{~_/;\p3
/* e{:86C!d)
**FileAccess.java '}@e5^oL
*//文件访问(定位，写) A}gYcc85Z
package NetFox; AVU7WU{
import java.io.*; zv`zsqDJ
(2cGHYU3N<
+J%6bn)U
public class FileAccessI implements Serializable{ %;'~%\|dZM
2$iw/r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QZ#3Bn%B5
RandomAccessFile oSavedFile; @h!U
long nPos; cxL,]27Bu
s87 a%
%C6|-?TAd
public FileAccessI() throws IOException m9%yR"g9
{ {`tHJ|8
this("",0); vY4WQbz(
} 0PR4g}"
l.sm~/
-6(h@F%E
public FileAccessI(String sName,long nPos) throws IOException 5sG ]3z+1
{ ]aREQ?ma&z
oSavedFile = new RandomAccessFile(sName,"rw"); *X%?3"WH8
this.nPos = nPos; L,f^mX0<
oSavedFile.seek(nPos); D`1I;Tb#
} Ml'bZLwq
FpwlV}:
[SKP|`I>I
public synchronized int write(byte[] b,int nStart,int nLen) $_ST:h&C
{ "vv$%^
int n = -1; B8`R(vu;
try{ t)YFTO"Jj
oSavedFile.write(b,nStart,nLen); PY[Sz=[
n = nLen; hgF21Oj9
} \x3^
catch(IOException e) J11dqj
{ Pw0{.W~r
e.printStackTrace (); kt;}]O2%R
} s4^[3|Zrr0
Iz 1*4@
Sr4dY`V*:z
return n; Uyz;U34 oI
} _HSTiJVr
8h55$j
mMel,iK=
} $_4oN(WSz
\Sz4Gr0g3Z
V22q*/iV
/* ---Ks0\V
**SiteInfoBean.java BnY\FQ)K
*/ V5hp Y ]
package NetFox; ?FkQe~FN{
N:m@D][/sW
JrY"J]/
public class SiteInfoBean { k#{lt-a/
9\\@I =;
~nLkn#Z
private String sSiteURL; //Site's URL f'7d4
private String sFilePath; //Saved File's Path .Y=Z!Q
private String sFileName; //Saved File's Name K8e4ax
private int nSplitter; //Count of Splited Downloading File ]L5Z=.z&
AJJ%gxqGq
EKeBTb
public SiteInfoBean() 3C E 39W
{//nSplitter的缺省值为5 F]dmc,Q
//default value of nSplitter is 5 UXcH";*9b
this("","","",5); >[A65q'
} u*#-7
GQEIf$
A>rWGo.{E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EZgxSQaPH
{ (h'$3~
sSiteURL= sURL; [wXwKr
sFilePath = sPath; /6Jy'"+'0
sFileName = sName; 4]|9!=\
this.nSplitter = nSpiltter; ~ wJ3AqNC?
wj5qQ]WC
2zmQp
} S)Ub/`f{s
b |o`Q7Hj
yg-L^`t+B5
public String getSSiteURL() x mrugNRg
{ WrIL]kJw^
return sSiteURL; 6Zl.Lh
} 8AC.2v?_
=:ya;k&
,?7xb]h
public void setSSiteURL(String value) e0G}$ as
{ lEVQA*u[
sSiteURL = value; 'p|Iwtjn>
} oF 1W}DtA
khKv5K#)
O>tC]sm%
public String getSFilePath() gKm@B{rC
{ U_N5~#9
return sFilePath; 7Y_fF1-wY
} m=("N
Sm*Jysy`
HL}sqcp
public void setSFilePath(String value) o[Wagg.%
{ G{&yzHAuae
sFilePath = value; O=!)})YG
} 5;sQ@
jx5[bUp4u
b}}1TnS)
public String getSFileName() ^J*G%*
{ o\=i0HR9
return sFileName; ib""Fv7{
} q|Pt>4c5?
eD` ,
f2SU5e2
public void setSFileName(String value) %FR^[H]
{ XeIUdg4>R
sFileName = value; 'o#J>a~!9L
} AD!<%h:
+ 8K1]'t$
ac+k 5K+
public int getNSplitter() G2[IO $
{ SCt=OdP=
return nSplitter; }?Yr>ZRi
} JtrDZ;^@
]L%R[Z!3
&[2Ej|o
public void setNSplitter(int nCount) x(/@Pt2B
{ SceCucT
nSplitter = nCount; 7gdU9c/q,
} KWn1%oGJ
} &xiDG=I#
DESViQM
LGo@F;!n
/* +~i+k~{`H
**Utility.java X gx2
*/ ~y-vKCp|
package NetFox; !7"K>m<
5qtmb4R~
EV?47\~
public class Utility { ZR01<V
R6WgA@Z|r
ah!O&ECh
public Utility() ]zwqGA
{ *|,ykb>
w;SH>Ax:
|q.:hWYFpM
} rJc)<OZjT
G=bP<XF
//线程睡眠 8HRPJSO~g
public static void sleep(int nSecond) pJ*#aH[ySP
{ Mn }Z9S[
try{ ("JV:u.L+
Thread.sleep(nSecond); 1J{z}yPHc
} gt t$O
catch(Exception e) w#G=Z_Tt
{ _AFt6\
e.printStackTrace (); eDM0417O(
} !qw=I(
} ~q_+;W.
@y\{<X.F\1
//日志 h@m n GE
public static void log(String sMsg) }fZ=T4r
{ moJT8tb
System.err.println(sMsg); y'2kV6TtqD
} 64\5v?C
:@@A
1-NX>E5
public static void log(int sMsg) dj'8x48H2W
{ l;Wy,?p
System.err.println(sMsg); ,<P[CUD&&
} *A1TDc$
} }jY[| >z
#!d^3iB2
R$;&O. 5M
/* YT(1 "{:
**TestMethod.java xm10
*/ % 6hw
package NetFox; Y7t{4P
C}P \kDM
?'/5%f`
public class TestMethod { ox=7N{+`J
, w'$T)
~h^}W$pO
public TestMethod() if!`Qid
{ ///xx/weblogic60b2_win.exe ;`PkmAg
try{ n\"LN3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >wS:3$Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E#2k|TpH4
SiteFileFetch fileFetch = new SiteFileFetch(bean); `w=H'"Zv
fileFetch.start(); dK;\`>8
} .kKwdqO+zB
catch(Exception e){e.printStackTrace ();} ~!d)J
,S0~:c:)
Mm7n?kb6
} q}F%o0
vBYT)S
CygV_q
public static void main(String[] args) L,A-G"z0Z
{ pOI`,i}.
new TestMethod(); 6p=xgk-q
} u r.T YKF
} y" 6~9j
点击下载更多相关资料