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)); g-|Kyhr?=
} Z9f/-|r5
for(int i=0;i<nEndPos.length-1;i++) <M305BH
{ B G5X_s0/
nEndPos = nStartPos[i+1]; /+29.1#|
} ]CIe~q
nEndPos[nEndPos.length-1] = nFileLength; E4Zxv*
} Iu%^*K%
} Iht'e8)gq
O$U}d-Xnx
UQnBqkE
//启动子线程 jm+blB^%K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Bs@:rhDi
for(int i=0;i<nStartPos.length;i++) 8W@dtZ,d
{ yWmrdvL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9BO|1{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7|{ B#
nStartPos,nEndPos,i); uct=i1+ fE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eX@v7i,}
fileSplitterFetch.start(); "&Gw1.p
} A`IHP{aB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \*Ts)EW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M$F{N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L7<+LA)s0
nEndPos = " + nFileLength); e|JIrOnc
// fileSplitterFetch[nPos.length-1].start(); e) ]RA?bF
pbPz$Y
G~S))p
//等待子线程结束 }\DAg'e)
//int count = 0; ,!r@9T
//是否结束while循环 *|^,DGfQ6
boolean breakWhile = false; ;}UzJe ,S
L,WkJe3
)O9fhj)
while(!bStop) WqR7uiCi
{ el}hcAY/RP
write_nPos(); X:U=MWc>
Utility.sleep(500); u |'8a1
breakWhile = true; k?<i*;7
ma1(EJ/
#s*k| j}
for(int i=0;i<nStartPos.length;i++) )=y.^@UT@
{ Q*Y4m8wY
if(!fileSplitterFetch.bDownOver) K[*h+YO
{ zUJx&5/
breakWhile = false; i},d[
break; ;4l-M2
} fjcr<&{:
} Bpm,mp4g\#
if(breakWhile) 0e)lY='^_
break; >CH
"oHp.$+K
xm^N8
//count++; k]t,q$Vd
//if(count>4) xna7kA
// siteStop(); ^)Smv\Md
} 1>hb-OMX
Ywmyr[Uh'
JaA&eT|
System.err.println("文件下载结束！"); `(P "u
} W8< @sq~I
catch(Exception e){e.printStackTrace ();} h]<GTWj
} 1X[73
?Y%}(3y
7F"3<U@J
//获得文件长度 n'q aR<bY
public long getFileSize() !&qx7eOSpP
{ H3!,d`D.N
int nFileLength = -1; t#a.}Jl
try{ 3xRM 1GgO
URL url = new URL(siteInfoBean.getSSiteURL()); x6"/z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C\y[&egww
httpConnection.setRequestProperty("User-Agent","NetFox"); nWKO8C>
7F,07\c
7We?P,A\;
int responseCode=httpConnection.getResponseCode(); f$Gr`d
if(responseCode>=400) yZ?xt'tn
{ JtSuD>H`"
processErrorCode(responseCode); @P*ylB}?Q
return -2; //-2 represent access is error ~o:rM/!Ba
} =s`XZkh
,?C|.5
&/ \O2Aw8
String sHeader; h1n*WQ-
c$@`P
d,zp`S
for(int i=1;;i++) Q1aHIc
{ 976E3u"Vt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); KX0<j
//Utility.log(in.readLine()); mk#>Dpy?
sHeader=httpConnection.getHeaderFieldKey(i); r3n=<l!Jr
if(sHeader!=null) UAnB=L,.\
{ fn4=
if(sHeader.equals("Content-Length")) 5T~3$kuO
{ s;vWR^Ll
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 98X!uh'
break; ?lu_}t]
} ,lrYl!,
} kEp.0wL'
else X(4s;i
break; <]Ij(+J;
} FgXu1-
} 29&sydu
catch(IOException e){e.printStackTrace ();} ^wvH,>Yo
catch(Exception e){e.printStackTrace ();} Gtj(
3?!G-
xR\D(FLVS
Utility.log(nFileLength); z8 hTZU
99\{!W
D=jSh
return nFileLength; Q2JdO 6[96
} RpBiE8F4
AM>Yj
p>2||
//保存下载信息（文件指针位置） j)g_*\tQ
private void write_nPos() i58ZV`Rk`
{ 5W*7qD[m
try{ O<}ep)mr
output = new DataOutputStream(new FileOutputStream(tmpFile)); }wvwZ`5t
output.writeInt(nStartPos.length); hubfK~
for(int i=0;i<nStartPos.length;i++) 9V|E1-")E
{ 1~["{u
// output.writeLong(nPos); | \ s2
output.writeLong(fileSplitterFetch.nStartPos); &p/S>qKu#
output.writeLong(fileSplitterFetch.nEndPos); :iP>z}h
} |pfhrwJp
output.close(); >t1_5
} QH@Q\ @,
catch(IOException e){e.printStackTrace ();} ..vSL
catch(Exception e){e.printStackTrace ();} o?:;8]sr!
} ;X?Ah
TYs+XJ'Xj
u5xU)l3
//读取保存的下载信息（文件指针位置） >wz;}9v
private void read_nPos() y#hga5
{ <;2P._oZ
try{ 8QkWgd7y
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kvMk:.
int nCount = input.readInt(); Qv9*p('~A
nStartPos = new long[nCount]; hgTM5*fD}
nEndPos = new long[nCount]; bYwI==3
for(int i=0;i<nStartPos.length;i++) g*:ae;GP
{ (|yRo
nStartPos = input.readLong(); Wl^prs7}c
nEndPos = input.readLong(); oUW)H
} nz,Mqol
input.close(); >i^y;5
} -X"5G
catch(IOException e){e.printStackTrace ();} tYI]LL
catch(Exception e){e.printStackTrace ();} V_)5Af3wY
} ^CowJ(y(
.Q=2WCv0
(z8]FT
private void processErrorCode(int nErrorCode) @-)<|orU4
{ \iFMU#
System.err.println("Error Code : " + nErrorCode); ?aK'OIo
} 6%\7.h
wMlf3Uz
e5*5.AB6&
//停止文件下载 |i,zY{GI+2
public void siteStop() OqfhCNAY
{ Bo\a
bStop = true; WUE)SVf
for(int i=0;i<nStartPos.length;i++) ^kCk^D-Gz
fileSplitterFetch.splitterStop(); -XS+Uv
KKx&UKjV
SR&(HH$
} #~bU}[{
} Zu2m%=J`
//负责部分文件的抓取 9IS1.3
**FileSplitterFetch.java l _kg3e4
*/ u4b3bH9U
package NetFox; LY@1@O2@
9TYw@o5V
&A ;3; R
import java.io.*; P?Gd}mdX?m
import java.net.*; `^XRrVX<
x'E'jh%
[?|l X$<
public class FileSplitterFetch extends Thread { lKh2LY=j
VTy,43<
_ 6+,R
String sURL; //File URL ?V&Ld$db
long nStartPos; //File Snippet Start Position F]K$u<U
long nEndPos; //File Snippet End Position I3}HNGvU
int nThreadID; //Thread's ID ]t.WJC %
boolean bDownOver = false; //Downing is over zh#OD{
boolean bStop = false; //Stop identical ue6/EN;}
FileAccessI fileAccessI = null; //File Access interface ,$MWk(S
nvO%
EuKrYY]g
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;#5-.z
{ 7AGZu?1]M
this.sURL = sURL; L:t)$iF5+
this.nStartPos = nStart; %KJ"rvi4K
this.nEndPos = nEnd; (c|$+B^*
nThreadID = id; Jf%!I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,mO(!D
} L337/8fh
7 SjF9x
~.PPf/ Z8]
public void run() !L0E03')k
{ ()JYN5
while(nStartPos < nEndPos && !bStop) !^Z[z[
{ -)y> c
*@bg/S K%
Xhq? 7P$3
try{ 7`uA
URL url = new URL(sURL); X <ba|(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `'G),{ j
httpConnection.setRequestProperty("User-Agent","NetFox"); ^G'yaaLXR
String sProperty = "bytes="+nStartPos+"-"; haEZp6Z
httpConnection.setRequestProperty("RANGE",sProperty); *#prSS
Utility.log(sProperty); \28b_,i+
~# hE&nq
)E[ Q
InputStream input = httpConnection.getInputStream(); M\Uc;:) H
//logResponseHead(httpConnection); 2HvTM8
+H)!uLvaB
V',m $
byte[] b = new byte[1024]; ^td!g1"<
int nRead; jt'Y(u]2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) S+_A <p
{ 0]:*v?
nStartPos += fileAccessI.write(b,0,nRead); J-eA,9J
//if(nThreadID == 1) 9:CVN@E
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~ X]"P4 u
} o5*74Mv
h|c:!VN@
T(sG.%
Utility.log("Thread " + nThreadID + " is over!"); Zi<Sw
bDownOver = true; QN2*]+/h
//nPos = fileAccessI.write (b,0,nRead); LhVLsa(-%
} cdek^/
catch(Exception e){e.printStackTrace ();} uusY,Dt/9
} :N*q;j>
} y:i[~y
5fvUv"m
C$2o o@
//打印回应的头信息 }OX>(
public void logResponseHead(HttpURLConnection con) G(7\<x:
{ o3TBRn,
for(int i=1;;i++) $dVgFot
{ lk+=26>
String header=con.getHeaderFieldKey(i); 6bRQL}[
if(header!=null) k<j)?_=`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); T|BY00Sz`
Utility.log(header+" : "+con.getHeaderField(header)); jziA;6uL
else 1v[#::Bs
break; _Sk<S
} ;8%@Lan
} bAy5/G!_R
st'?3A
$:-= >
public void splitterStop() #/XK&(X
{ }'w^<:RSy
bStop = true; G8<It5CU
} ]mD=Br*r~
8ZNd|\
e$/Zb`k
} qN`]*baS
J<5vs3[9
vUIK4uR.
/* tI!R5q;k
**FileAccess.java bb O;AiHD
*//文件访问(定位，写) soQv?4
package NetFox; !Lg}q!*%>V
import java.io.*; w=P<4bdT
[r/Seg"
`aX}.{.!
public class FileAccessI implements Serializable{ kGBl)0pr`x
d'g{K]=tF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v0jz)z<#
RandomAccessFile oSavedFile; j9L+.UVI,
long nPos; *>&N t
"` ?Wu
'bY|$\I
public FileAccessI() throws IOException ! 4^L $
{ q2j}64o_S
this("",0); B'BbTI,
} iqv\ag
k`4\.m"&
E*T84Jh6
public FileAccessI(String sName,long nPos) throws IOException T=f;n;/>
{ DRmh(T
oSavedFile = new RandomAccessFile(sName,"rw"); e,j?_p
this.nPos = nPos; L&gEQDPgq|
oSavedFile.seek(nPos); k~9Ywf
} $qyM X[
>G3J3P(
TeN1\rA,
public synchronized int write(byte[] b,int nStart,int nLen) #V9hG9%8
{ OHtZ"^YG
int n = -1; hDkqEkq1R
try{ ~NW5+M(u
oSavedFile.write(b,nStart,nLen); [2j(\vC!
n = nLen; H R!>g
} :PjUl
catch(IOException e) G'}_ZUy#
{ &LxzAL,3!
e.printStackTrace (); /jL{JF>I
} RVKaqJ0e<
pt|$bU7
;Q,).@<C
return n; |s3HeY+Co
} PS<tS_.
W-ND<=:Up
,"MUfZ
} 7Hkf7\JY
Xi`U`7?D(=
[@FeRIu8
/* ^CZ|ci6bX
**SiteInfoBean.java #y9K-}u
*/ ^[\53\R~
package NetFox; Ew,wNR`
[,A'
m"m;(T{ v
public class SiteInfoBean { Ug'nr
uu/7Ie
0@/E%T1c"
private String sSiteURL; //Site's URL m&z%kVsg]
private String sFilePath; //Saved File's Path 7;s0m0<%~
private String sFileName; //Saved File's Name ;51!aC
private int nSplitter; //Count of Splited Downloading File #&8pp8wd,}
,HO/Q6;N
czsoD)N
public SiteInfoBean() ^l2d?v8
{//nSplitter的缺省值为5 _TcQ12H 5<
//default value of nSplitter is 5 i.dAL)V
this("","","",5); P;91C'T-x
} ]}Hv,a
^d$e^cU
U &k3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Pc ?G^ Xol
{ GDQg:MgX
sSiteURL= sURL; 2uR4~XjF
sFilePath = sPath; sL`D}_:
sFileName = sName; 6o23#JgN
this.nSplitter = nSpiltter; S@2Jj>3D?
NeZYchR
F4{. 7BT
} 7ofH@U
\^W?
(']z\4o
public String getSSiteURL() exN#!&;
{ oW1olmpp=
return sSiteURL; D~?*Xv]s~
} &$Ip$"H
2<./HH*f
;}9Ws6#XQs
public void setSSiteURL(String value) ^p%+rB.j[
{ jP6G.aiO
sSiteURL = value; m<LzB_G\
} :<3;7R'5
$zA[5}{ZtQ
q'-l;V|
public String getSFilePath() WG=r? xE
{ LO*a>9LI
return sFilePath; GT}#iM
} xfQ;5n
`ZV'7|
;j\$[4W.i
public void setSFilePath(String value) ~(P\F&A(&
{ >h-6B=
sFilePath = value; .{ Lm
} 3'uES4+r
Z"nuO\zH~
x(6.W"-S
public String getSFileName() A/6nVn
{ zQ^[=siZ}
return sFileName; 6C}Z1lZl
} BqAwo
nE.s
bGnJ4R3J
public void setSFileName(String value) ebwoMG,B-
{ hUvH t+d
sFileName = value; <.XoC?j
} ,(?4T~
RwHXn]1
Os]M$c_88
public int getNSplitter() j~> #{"C
{ qiJ;v1
return nSplitter; j0NPd^
} HpSfI7
lFt{:HfX-
.tZ$a_O
public void setNSplitter(int nCount) 9e*poG
{ z]_CFo1'l
nSplitter = nCount; MNE)<vw>
} jl29~^@}1i
} ~OfKn1D
wWswuhq<
O@&I.d$
/* tELnq#<6
**Utility.java 56aJE .?<
*/ ".Z+bi2l
package NetFox; "2j~3aWj
vv_?ip:t
*M5C*}dl
public class Utility { uT2cHzqKB
;8kfgpM_
@}RyW&1Z
public Utility() 2xm?,p`
{ du)G)~
?%n9g)>Yej
v)pWx0l=
} W]]2Uo.
t$%}*@x7
//线程睡眠 (G'ddZAJV
public static void sleep(int nSecond) ,urkd~
{ :Dm@3S$4<
try{ 8)ol6Mi{
Thread.sleep(nSecond); ]c+'SJQ
} >u[ln@ l
catch(Exception e) :fUmMta
{ 6-}9m7#Y
e.printStackTrace (); -^N '18:
} %"B$I>h
} CtxK{:
j KK48S
//日志 ^jC0S[csw2
public static void log(String sMsg) ovVU%2o1b
{ }RK9Onh3G
System.err.println(sMsg); |%9~W^b
} 0$ EJ4
|a3b2x,
--D`YmB
public static void log(int sMsg) IC42O_^
{ 69L&H!<i:
System.err.println(sMsg); 5Ep
} 3<lDsb(}0A
} yV`vu/3K
?+_"2XY
(ZJ_&8C#
/* > [7vXm4
**TestMethod.java '?4[w]0J<
*/ O#k+.LU
package NetFox; :oQaN[3>_
G_RK3E[FK
T[J_/DE@
public class TestMethod { yK;I<8+>_
X} 8U-N6)
b*7i&q'H
public TestMethod() z""(M4
{ ///xx/weblogic60b2_win.exe !b_IH0]U
try{ tL|Q{+i yE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W[DB!ue
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ja2.1v|r.
SiteFileFetch fileFetch = new SiteFileFetch(bean); nwYeOa/t
fileFetch.start(); ?Ci\3)u,P
} z@}~2K
catch(Exception e){e.printStackTrace ();} X*&r/=
`^x^= og'
M,P_xkLp
} &v88xs
b1"wQM9
oKiu6=
public static void main(String[] args) &aU+6'+QXB
{ 8iB}a\]B
new TestMethod(); uNDkK o<M
} R7>@-EG
} p-_j0zv
点击下载更多相关资料