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)); s 4n<k]d
} i1!Y{
for(int i=0;i<nEndPos.length-1;i++) &0OH:P%
{ B.#-@
nEndPos = nStartPos[i+1]; >bg{
} hfs QAa
nEndPos[nEndPos.length-1] = nFileLength; .GvZv>
} {T3wOi
} X @X`,/{X
iN2591S
ucUuhS5
//启动子线程 #_zj5B38E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jIWX6
for(int i=0;i<nStartPos.length;i++) T;3B_lu]
{ /Ur]U w
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rj-4K@a8#N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^O**ZndB/
nStartPos,nEndPos,i); Cf@N>N#t)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3vEwui-5
fileSplitterFetch.start(); +xNq8yS
} I<S*"[nV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u89Q2\z~"M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )Zrn?KM
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |Rb8/WX
nEndPos = " + nFileLength); #2%8@?_-M
// fileSplitterFetch[nPos.length-1].start(); *\^(-p~M
pK)!o
q[c^`5
//等待子线程结束 F`o"t]AD-a
//int count = 0; * K0aR!
//是否结束while循环 f_IsY+@
boolean breakWhile = false; -90X^]
%/RT}CBBsW
c\rP"y|S};
while(!bStop) rC6EgWt<V
{ wLo<gA6;
write_nPos(); 8>DX :`
Utility.sleep(500); cq8JpSB(
breakWhile = true; kM3#[#6$!
Jv~^hN2
s_U--y.2r(
for(int i=0;i<nStartPos.length;i++) %\!@$]3q
{ {Vf].l:kn
if(!fileSplitterFetch.bDownOver) xxpzz(S ]A
{ I1JF2"{c
breakWhile = false; mA5sK?W
break; \Lm`jU(:l
} "f-HOd\=
} M?I^`6IOc8
if(breakWhile) {ApjOIxk
break; H2CpZK'
gVs@T'
P@U2Q%\
//count++; 5zH_yZ@+
//if(count>4) Om2w+yU
// siteStop(); 66scBi_d
} O?iLLfs
]m#*4
i_p-|I:hQ
System.err.println("文件下载结束！"); a!,X@5
} G1wJ]ar
catch(Exception e){e.printStackTrace ();} 7~VDk5Z6
} m5cRHo<9Y
n"nfEA3{`
"FLiSz%ME
//获得文件长度 K/8TwB?I
public long getFileSize() I\|.WrMNi
{ cPX^4d~9
int nFileLength = -1; {6>$w/+~
try{ *Z3b6X'e
URL url = new URL(siteInfoBean.getSSiteURL()); B\+uRiD8w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MZ>Q Rf
httpConnection.setRequestProperty("User-Agent","NetFox"); k!d<2Qp W
[NbW"Y7
Cw~fP[5XMF
int responseCode=httpConnection.getResponseCode(); t_\&LMD
if(responseCode>=400) H"wIa8A
{ Rp6q)
processErrorCode(responseCode); =|H.r9-PK6
return -2; //-2 represent access is error V2$M`|E
} '|G8yojz
[x -<O:r=P
{N@Pk[!
String sHeader; G}@a]EGm
)g`~,3G
~Sx\>wBlc
for(int i=1;;i++) 6ck%M#v
{ 6u{%jSA>D\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]6,D9^{;
//Utility.log(in.readLine()); 3]kN9n{
sHeader=httpConnection.getHeaderFieldKey(i); 40 zO4
if(sHeader!=null) mcxD#+H 3
{ )QI#szv6
if(sHeader.equals("Content-Length")) 7nZ3u_~
{ Nwk^r75lq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \Npvm49
break; ow#8oUf=
} ]N:Wt2
} E|W7IgS
else Us% _'}(/U
break; ?h,.1Tb
} KIY9?B=+
} o 9d|XY_
catch(IOException e){e.printStackTrace ();} ul!q)cPb{
catch(Exception e){e.printStackTrace ();} X#o;`QM
_.SpU`>/f
[<nd+3E
Utility.log(nFileLength); )-25?B
`tl-] ^Y2
fP llN8n
return nFileLength; qf{HGn_9~1
} mv(/M t
^grDP*;W
ulfs Z:
//保存下载信息（文件指针位置） #p-\Y7f
private void write_nPos() *pyC<4W
{ ?5wsgP^
try{ .p(r|5(b
output = new DataOutputStream(new FileOutputStream(tmpFile)); WZ UeW*#=
output.writeInt(nStartPos.length); LVdtI
for(int i=0;i<nStartPos.length;i++) nIqF:6/
{ A:5P
// output.writeLong(nPos); X,D ]S@
output.writeLong(fileSplitterFetch.nStartPos); w{GEWD{&
output.writeLong(fileSplitterFetch.nEndPos); kB=5=#s
} %Lq}5zB
output.close(); ypx`!2Q$
} A>\3FeU>UC
catch(IOException e){e.printStackTrace ();} (R(NEN
catch(Exception e){e.printStackTrace ();} Bk5ft4v-
} i*mI-l
}sp?@C,Z
AnpO?+\HF
//读取保存的下载信息（文件指针位置） ,_K:DSiB
private void read_nPos() Uh'W d_?
{ >2NsBS(
try{ YB(8 T"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k7M{+X6[
int nCount = input.readInt(); UU '9
nStartPos = new long[nCount]; Y]i:$X]C?X
nEndPos = new long[nCount]; W9{y1,G9
for(int i=0;i<nStartPos.length;i++) m<!CF3g
{ #hXuGBZEI
nStartPos = input.readLong(); !04^E
nEndPos = input.readLong(); pqe%tRH{
} FA;B:O@:'
input.close(); JvS ~.g1
} KVoM\ttP
catch(IOException e){e.printStackTrace ();} AOx8OiqE:
catch(Exception e){e.printStackTrace ();} 'Y]<1M>.g
} n,{
${`q!
GqgJ]m
private void processErrorCode(int nErrorCode) e'|c59E
{ 2hTsjJ!'
System.err.println("Error Code : " + nErrorCode); (A-Uo
} y|3!E>Up
'Z nJdj
etk|%%J
//停止文件下载 oUB9)C~
public void siteStop() mFE7#OM
{ p$<){,R
bStop = true; <)oxs]<
for(int i=0;i<nStartPos.length;i++) 4}]In/yA
fileSplitterFetch.splitterStop(); !k#N] 9D3
|@hyGu-H+
@Y#TWt#
} :^]FpUY
} ^b*ub(5Ot
//负责部分文件的抓取 am/D$ (l1
**FileSplitterFetch.java 2SKtdiY
*/ ;`Z>^.CB
package NetFox; B9'2$s+Z;
S}K-\[i?
'Y/8gD~.
import java.io.*; eYPIZ{S7h
import java.net.*; Gz7,g Y
&+/$~@OK
Zm#,Ike?#
public class FileSplitterFetch extends Thread { ""jl
RI BB*
+:u &]
String sURL; //File URL NSQ)lSW,;
long nStartPos; //File Snippet Start Position M*dou_Q
long nEndPos; //File Snippet End Position FQcm=d_s
int nThreadID; //Thread's ID Z-aB[hE
boolean bDownOver = false; //Downing is over Q|f)Awe$
boolean bStop = false; //Stop identical :kXxxS
FileAccessI fileAccessI = null; //File Access interface zF&_9VNk=c
q\Z9.T+Qo
%@%~<U)W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;!EEzR.
{ ppO!v?
this.sURL = sURL; *k0;R[IAV
this.nStartPos = nStart; aI\]R:f,
this.nEndPos = nEnd; A \Z_br
nThreadID = id; G ahY+$L,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c43&[xPLz
} q4Y'yp`?K;
~:-V<r,pe
axv-UdE;
public void run() "rw'mogRL
{ 7QaZ|\c
while(nStartPos < nEndPos && !bStop) A$TFa:O|
{ d)0 hAdh
@! jpJ}
N Q}5'
try{ :oJ!9\5
URL url = new URL(sURL); UQjZhH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RI]x=
httpConnection.setRequestProperty("User-Agent","NetFox"); $EZr@n
String sProperty = "bytes="+nStartPos+"-"; h5[.G!
httpConnection.setRequestProperty("RANGE",sProperty); ^_o:Ddz?l"
Utility.log(sProperty); = Ruq
!1P<A1K
t0)hdX
InputStream input = httpConnection.getInputStream(); mm N$\2
//logResponseHead(httpConnection); 5(y Q-/6C+
~bfjP2 g
l{. XhB
byte[] b = new byte[1024]; 5NMju!/
int nRead; X{qa|6S,F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'WwD$e0=
{ 7Y^2JlZu=
nStartPos += fileAccessI.write(b,0,nRead); 'zuA3$SR
//if(nThreadID == 1) dV"Kx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &I/C^/F&
} i.+#a2
AUR{O
5ma~Pjt8}
Utility.log("Thread " + nThreadID + " is over!"); hy@e(k|S]U
bDownOver = true; > Cx;h=
//nPos = fileAccessI.write (b,0,nRead); _Tf0L<A'R
} z!^3%kJJ>
catch(Exception e){e.printStackTrace ();} MUp{2_RA
} /fxv^C82yv
} -yY]0
?gS~9jgcd
u~27\oj,
//打印回应的头信息 ~<=wTns!
public void logResponseHead(HttpURLConnection con) 8uB6C0,6?
{ *w1R>
for(int i=1;;i++) M532>+A]Za
{ *)i+c{~
String header=con.getHeaderFieldKey(i); HE3x0H}o>
if(header!=null) Il!#]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tEllkHyef
Utility.log(header+" : "+con.getHeaderField(header)); 6CzN[R}
else k7bfgb{
break; 3yM!BTlX
} "C]_pWk
} _^Q =n>G
1$uO%
9K#U<Q0b'
public void splitterStop() )7iYx{n
{ @.KFWAm
bStop = true; fMZc_dsW9
} YGkk"gFIA
~)!vhdBe
[1.>9ngj
} ](^BQc
iR4!X()
t%30B^Ii%K
/* 2@pEuB3$?!
**FileAccess.java 2L?Pw
*//文件访问(定位，写) B6]M\4v
package NetFox; y3mJO[U0 a
import java.io.*; 9X87"
yv.(Oy
EN~ha:9
public class FileAccessI implements Serializable{ hkR Jqta)
q=uJ^N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mV'^4by
RandomAccessFile oSavedFile; )Jd{WC.
long nPos; m#t
(J\Qo9Il
3AarRQWsn
public FileAccessI() throws IOException 1EA}[x
{ m-}6DN
this("",0); ZbLN:g}
} _iW-i
/Wm3qlv
4(}V$#^+
public FileAccessI(String sName,long nPos) throws IOException (khMjFOg
{ {#uf#J|
oSavedFile = new RandomAccessFile(sName,"rw"); 5\P3JoH:Yg
this.nPos = nPos; W8s/"
oSavedFile.seek(nPos); h%(0|
} oA$]%
I=wA)Bli1p
X5Ff2@."y|
public synchronized int write(byte[] b,int nStart,int nLen) ^[-3qi
{ \d"M&-O
int n = -1; Mj-B;r
try{ tvvRHvL
oSavedFile.write(b,nStart,nLen); t[?O*>
n = nLen; u7ER
} /km'#f)/
catch(IOException e) $eUJd Aetk
{ **lT 'D
e.printStackTrace (); # >L^W7^
} *heX[D &>)
wUbLw
>EIV`|b$h
return n; 9Y-6e0B:
} RF.8zea{O`
;l2pdP4jf
pbb6?R,
} F5;x>;r
<ooRpn
*[[TDduh&
/* <)$b=z
**SiteInfoBean.java <MoKTP-<
*/ @mrGG F
package NetFox; LzJNQd'
!)TO2?,^
,mW-O!$3W
public class SiteInfoBean { 8t Ef>
G/5]0]SO
0'.7dzz
private String sSiteURL; //Site's URL \3v}:E+3
private String sFilePath; //Saved File's Path ITu5Y"x
private String sFileName; //Saved File's Name \Z%V)ZRi=
private int nSplitter; //Count of Splited Downloading File ImVHX~qHJ
.|9o`mF7
74q|FQ
public SiteInfoBean() 4w-P%-4
{//nSplitter的缺省值为5 I4"U/iL51
//default value of nSplitter is 5 G Za<
this("","","",5); U:o(%dk
} A('_.J=
pJ 7="n
*ioVLt,:R
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) C[h^bBq
{ qCaM]Y
sSiteURL= sURL; X6g{qzHg_
sFilePath = sPath; B'"RKs]
sFileName = sName; 5Myp#!|x:
this.nSplitter = nSpiltter; N3}jLl/
=/jCDY
H%AC *,
} >k{KwFB^S
e+=P)Zp/
YjM_8@<
public String getSSiteURL() >m;*Zk`
{ '-[~I>o%
return sSiteURL; p+>vX X
} YKT=0
Pwh0Se5Z
9:tn!<^=I
public void setSSiteURL(String value) #fR~7KR
{ XY1eeB-
sSiteURL = value; nm597WeZp
} 8hx 3pvmk
Rg?m$$X`
~9KxvQzt
public String getSFilePath() 1-M\K^F
{ \P` mV9P
return sFilePath; CnA0^JX
} 6#rj3^]
j >wT-s
`K^j:fE7n
public void setSFilePath(String value) 8P#jC$<
{ DNN60NX 5Q
sFilePath = value; ?g21U97Q
} Y$SwQ;wl
y! lEGA7
Os# V=P
public String getSFileName() J_=42aHO
{ M)1?$'Aq
return sFileName; T8ftBIOi
} ^5yFb=2
lB Y"@N
L~])?d
public void setSFileName(String value) 3\Ma)\>R\-
{ [Q=NGHB1/
sFileName = value; K!MIA
} |tkhsQ-;
`>mT/Rmb@
LYv$U;*+
public int getNSplitter() ^Q'^9M2)
{ A=5A8B1
return nSplitter; jK{)gO
} \:/:S"-
3Y}X7-|)Z
CQ+WBTiC
public void setNSplitter(int nCount) {IlX@qWr
{ +80yyn#
nSplitter = nCount; s}pn5zMp:8
} ,?Bo x
} ~A5MzrvIO2
s$s]D\N
eviv,
/* .jfkOt?2
**Utility.java _ IqUp Y
*/ Jn>6y:s
package NetFox; C/w!Y)nB=
Xt!%W
lQolE P.pc
public class Utility { zu~E}
wSMP^kG
/5y*ZIq]e
public Utility() ]^63n/Twj
{ 2sOV3~bB
vZQ'
>lRa},5(
} ]ctlK'.
*0 0K3
//线程睡眠 ?1z." &
public static void sleep(int nSecond) uD2v6x236
{ Ris5)*7
try{ g`}+K U
Thread.sleep(nSecond); QQ5G?E
} b@yGa%Gz@
catch(Exception e) -2dk8]KB]
{ <3;Sq~^
e.printStackTrace (); ) DzbJ}
} ,c%>M^d
} 7n1@m_7O
)K4A-9pC
//日志 j(`L)/|O
public static void log(String sMsg) ].j;d2xT\
{ m&H@f:
System.err.println(sMsg); #sOkD
} ItZqLUJm
Fnnk}I}
1%?J l~M
public static void log(int sMsg) J1?)z+t9~
{ PN!NB.
System.err.println(sMsg); >^8=_i !
} =c-,uW11[
} 1?6;Oc^
[HKTXF{n
f\ wP}c'
/* d{UyiZm\
**TestMethod.java ^b{w\HZ
*/ Wn(pz)+Y
package NetFox; c({V[eGY
JO4rU- n
Pw^lp'dO
public class TestMethod { ZR~ *Yofy
wz-#kH5?
HbRDa
public TestMethod() p/4\O
{ ///xx/weblogic60b2_win.exe '\$2+*
try{ 4v"9I(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |z!Y,zaX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0u]!C"VX
SiteFileFetch fileFetch = new SiteFileFetch(bean); Xgge_`T9
fileFetch.start(); ] Fx9!S
} 1]L 0r
catch(Exception e){e.printStackTrace ();} C0xjM0
hcvWf\4'#q
>i>%@
} rpk )i:k\
U{2[nF
~>af"<
public static void main(String[] args) eB`7C"Z
{ ohFUy}y
new TestMethod(); -I$qe Xy
} 6gLk?^.
} t,mD{ENm&
点击下载更多相关资料