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)); 5E\#%K[
} +YY8h>hj
for(int i=0;i<nEndPos.length-1;i++) 83~ i:+;
{ pcS+o
nEndPos = nStartPos[i+1]; b}9[s
} FwAKP>6*
nEndPos[nEndPos.length-1] = nFileLength; | $^;wP
} U 5w:"x
} LHCsk{3
w?vVVA
.Ce8L&cU
//启动子线程 OWjJxORB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; . v)mZp
for(int i=0;i<nStartPos.length;i++) *V^ #ga#A
{ &[R8Q|1j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8^^[XbH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MhEw _{?
nStartPos,nEndPos,i); !eR3@%4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S0/usC[r
fileSplitterFetch.start(); $P o}
} V3N0Og3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cR{>IH4^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4'pS*v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2C^B_FUg|]
nEndPos = " + nFileLength); LE^G&<!
// fileSplitterFetch[nPos.length-1].start(); [s1pM1x
P'Q$d+F,
m*0,s
//等待子线程结束 L6P1L)
//int count = 0; DC+wD Bp;
//是否结束while循环 SS|z*h Z
boolean breakWhile = false; ;oOv/3
v`[Eb27W.
N^0uit
while(!bStop) i8X`HbmN
{ CG]Sj*SA~
write_nPos(); :,pSWfK H
Utility.sleep(500); 4-Z()F
breakWhile = true; ;$j7H&UNQj
Btt]R
Yepe=s+9
for(int i=0;i<nStartPos.length;i++) ?kw&=T!
{ al9.}
if(!fileSplitterFetch.bDownOver) \(UKdv
{ L#[]I,
breakWhile = false; Z{NC9
break; VObrlOkp
} j5$BK[p.
} bF}V4"d,B3
if(breakWhile) `<"m%>
break; 9Mm!%Hu
yR~-k?7b
iX{G]< n
//count++; 1t[j"CG(o
//if(count>4) 9a$56GnW1
// siteStop(); {NM+Oj,~'
} )QiQn=Ce
`em9T oJV
SF]@|
System.err.println("文件下载结束！"); FE7)E.U
} rEZ8eeB[3
catch(Exception e){e.printStackTrace ();} 5 LP?Ij
} m#H3:-h,
Ei>m0 ~<\
C_:k8?
//获得文件长度 AF,BwLN
public long getFileSize() HG>j5
{ Br>Fpe$q4
int nFileLength = -1; u~zs* qp
try{ lb'Cl3H
URL url = new URL(siteInfoBean.getSSiteURL()); F9q8SA#"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7\ SUr9[
httpConnection.setRequestProperty("User-Agent","NetFox"); BZK`O/
[|`U6 8}u
-_VG;$,jE
int responseCode=httpConnection.getResponseCode(); 3*S{;p
if(responseCode>=400) ?ne_m:J[
{ R! s6% :Yg
processErrorCode(responseCode); oSb, :^Wl
return -2; //-2 represent access is error >n5:1.g
} xh@-g|+g
eBN)g^
g\oSG)
String sHeader; 3#kitmV
"v*8_El
L}{`h
for(int i=1;;i++) \Xrw"\")j
{ k5d\w@G"~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &.i^dO^}
//Utility.log(in.readLine()); IputF<p
sHeader=httpConnection.getHeaderFieldKey(i); LS>G4 ]
if(sHeader!=null) =8G&3 R
{ pj|pcv^
if(sHeader.equals("Content-Length")) Q'B6^%:<~
{ tS# `.F~y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5 +9Ze9
break; :bU(S<%M
} Ac k}QzXO
} :HViX:]H
else +~Cy$MCX
break; /x@RNdKv
} c2SC|s]
} ^W83ByP
catch(IOException e){e.printStackTrace ();} zRl~^~sY
catch(Exception e){e.printStackTrace ();} DLPUqKL]
+';>=hha
"L"150Ih
Utility.log(nFileLength); {43yb_B(
Z5G!ct:W
kQdt}o])
return nFileLength; &7?R+ZGo
} DsDzkwJE
z;u> Yz+3
0CvsvUN@
//保存下载信息（文件指针位置） t/i5,le
private void write_nPos() C2e.2)y
{ %n0;[sD0A
try{ UnWW/]E
output = new DataOutputStream(new FileOutputStream(tmpFile)); T0HuqJty
output.writeInt(nStartPos.length); W\*-xf|"d
for(int i=0;i<nStartPos.length;i++) }b3/b
{ 1-SVCk -
// output.writeLong(nPos); A!W0S
output.writeLong(fileSplitterFetch.nStartPos); d?idTcgs
output.writeLong(fileSplitterFetch.nEndPos); "GT4s?6O
} @!=\R^#p
output.close(); gA#RM5x@
} {Ng oYl
catch(IOException e){e.printStackTrace ();} )+I.|5g
catch(Exception e){e.printStackTrace ();} @# P0M--X
} vP!GJX&n5
mumXUX
]pA(K?Lbg
//读取保存的下载信息（文件指针位置） : DG)g3#
private void read_nPos() *2"6fX[
{ rk2xKm^w
try{ }|)R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C@y8.#l
int nCount = input.readInt(); AS!6XT
nStartPos = new long[nCount]; 5,"l0nrk
nEndPos = new long[nCount]; 3{Nbp
for(int i=0;i<nStartPos.length;i++) %rQuBi# 1f
{ `\>.h
nStartPos = input.readLong(); Lr;(xw\['
nEndPos = input.readLong(); z~6y+
} z1OFcqm
input.close(); UQCo}vM
} < O*6T%;
catch(IOException e){e.printStackTrace ();} ;d.K_P
catch(Exception e){e.printStackTrace ();} Q }k.JS~#
} 8Chj w wB
*TW=/+j
KP;(Q+qTx
private void processErrorCode(int nErrorCode) Uh}seB#mJj
{ d87vl13
System.err.println("Error Code : " + nErrorCode); V5}nOGV9
} V2Q$g^X'
SD\= m/W
/{2*WI;
//停止文件下载 }n,Zl>T9
public void siteStop() Myat{OF
{ qMBR *f
bStop = true; Is<"OQ
for(int i=0;i<nStartPos.length;i++) 1&=0Wg0ig
fileSplitterFetch.splitterStop(); ;.sl*q1A
.k{ j]{k
u#7+U\
} Q~D`cc|]
} IHfzZHy
//负责部分文件的抓取 `L;eba
**FileSplitterFetch.java MjfFf} @
*/ l*b)st_p%
package NetFox; PQW(EeQ
Gnm4gF!BI
- "*r
import java.io.*; BDY}*cX
import java.net.*; >Y 1{rSk
K[\'"HyQ,X
.ujT!{>v/
public class FileSplitterFetch extends Thread { yj6@7@l>A
X#a`K]!B
57{oh")
String sURL; //File URL {)f~#37
long nStartPos; //File Snippet Start Position UnDgu4#R`A
long nEndPos; //File Snippet End Position DQ.v+C,
int nThreadID; //Thread's ID /(I*,.d
boolean bDownOver = false; //Downing is over r5&I? 0
boolean bStop = false; //Stop identical \b'xt
FileAccessI fileAccessI = null; //File Access interface inPJ2uBD\^
u.pxz8
SxgYjIa-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I7QCYB|
{ :A46~UA!$
this.sURL = sURL; :^ i9]
this.nStartPos = nStart; '+'CbWgY
this.nEndPos = nEnd; <<9Va.
nThreadID = id; ! ueN|8'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I[MgIr^
} Z{IUy
0rk]/--FGJ
^_I} x)i*@
public void run() M/D)".;
{ <BWkUZz\P|
while(nStartPos < nEndPos && !bStop) pZZgIw}aS
{ j;yf8Nf
&MR/6"/s
z9 u$~
try{ k?BJdg)xJ
URL url = new URL(sURL); qVjWV$j
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5lKJll^2:
httpConnection.setRequestProperty("User-Agent","NetFox"); %ugHhS!
String sProperty = "bytes="+nStartPos+"-"; 1 "TVRb
httpConnection.setRequestProperty("RANGE",sProperty); =6FUNvP#8
Utility.log(sProperty); z><5R|Gf
o{v&.z
(%CZ*L[9Z
InputStream input = httpConnection.getInputStream(); Ph&urxH@
//logResponseHead(httpConnection); P27%xV-n>
3T\l]? z
`"yxdlXA
byte[] b = new byte[1024]; {C`GW}s{4
int nRead; :WGtR\tK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6SJ"Tni8
{ P=N$qz$U
nStartPos += fileAccessI.write(b,0,nRead); $FH18
//if(nThreadID == 1) K)7zKEp`cj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MOn,Db$
} -${DW^txMZ
+@9gkPQQ-@
1L7{p>;-dO
Utility.log("Thread " + nThreadID + " is over!"); C<^YVeG
bDownOver = true; D\~zS`}
//nPos = fileAccessI.write (b,0,nRead); }F6<w{|
} EO|:FcW
catch(Exception e){e.printStackTrace ();} 9Ywpej*+
} JuRH>`
} PW(\4Q\
0oA{Jix
qM4c]YIaSl
//打印回应的头信息 S|V4[ssB
public void logResponseHead(HttpURLConnection con) [./6At&|
{ }/dRU${!
for(int i=1;;i++) ubsSa}$q
{ #BVtL :x@
String header=con.getHeaderFieldKey(i); I:&/`K4,x,
if(header!=null) snM Z0W
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P;ZU-G4@
Utility.log(header+" : "+con.getHeaderField(header)); QB!~Wh
else @K223?c8l
break; [$(%dV6O
} h-a!q7]l
} rj]F87"
))D:8l@
.D,p@4
public void splitterStop() g]@(E
{ iO/XhSD
bStop = true; |LG4=j.l
} <>xJn{f0c
Xm2\0=v5;
j!~l,::$"X
} Kyt)2p
hD,:w%M
in <(g@Zg
/* $\o{_?}1
**FileAccess.java vgt]:$
*//文件访问(定位，写) m~#!
package NetFox; NvE}eA#
import java.io.*; UEs7''6RM
%t=kdc0=_
2=0DCF;Bv
public class FileAccessI implements Serializable{ A,-6|&F
;a=w5,h:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?PA$Ur21lw
RandomAccessFile oSavedFile; K`&oC8p
long nPos; N/YWby=H
75nNh~?)\
v`J*ixZ7t
public FileAccessI() throws IOException J2q,7wI#
{ 4!Z5og1kn
this("",0); m`#Od^vk
} vzzE-(\\e
RpG+>"1]
JTqDr
public FileAccessI(String sName,long nPos) throws IOException _iKq~\v2
{ HD,xY4q&N
oSavedFile = new RandomAccessFile(sName,"rw"); .Ig+Dj{)
this.nPos = nPos; cEW0;\$
oSavedFile.seek(nPos); 2M<R(W!&
} wS+V]`b
<H3ezv1M
q/3ziVd7p
public synchronized int write(byte[] b,int nStart,int nLen) TlAR.cV
{ H>Q%"|
int n = -1; &*G<a3Q
try{ j.~!dh$mg
oSavedFile.write(b,nStart,nLen); (Q[fS:U
n = nLen; 76tdJ!4Z
} \y6OUM2y
catch(IOException e) `.x$7!zLC
{ .Xm(D>>k
e.printStackTrace (); ~AYN
} sb:d>6
Y3kA?p0
r`&-9"+
return n; ?1L.:CS
} [=O/1T
)}Q(Tl\$
Gir#"5F
} =U[3PC-N@
i 8!zu!-0
Z UKf`m[
/* Ze<K=Q%(i
**SiteInfoBean.java UT~a&u
*/ tqAd$:L
package NetFox; @3fn)YQ'
NC&DFJo
G6VF>2
public class SiteInfoBean { &<zd.~N"
gh`m*@
`&0Wv0D0
private String sSiteURL; //Site's URL ]v[|B
private String sFilePath; //Saved File's Path T|&[7%F3"
private String sFileName; //Saved File's Name PFUO8>!pA\
private int nSplitter; //Count of Splited Downloading File }:: S0l
l1ZY1#%j
PcB_oG g
public SiteInfoBean() f>BWG`
{//nSplitter的缺省值为5 F4=}}kU
//default value of nSplitter is 5 |+ N5z
this("","","",5); )9,
} ys_`e
l4T7'U>`
FZreP.2)!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vVGDDDz/
{ _%'},Xd.z
sSiteURL= sURL; gTRF^knrY
sFilePath = sPath; ' |-JWH
sFileName = sName; wf,7==
this.nSplitter = nSpiltter; TJE\A)|>g
6y%0`!
Y@'8[]=0
} Gm*X'[\DD
5cx#SD&5/
}@if6(0
public String getSSiteURL() Qf@I)4'
{ u3Gjg{-N7
return sSiteURL; A^Kbsc
} +cb6??H
.q+0pj
No2b"G@
public void setSSiteURL(String value) S9HwIH\m
{ }68i[v9Njk
sSiteURL = value; Nn>'^KZNG
} =PGs{?+&O
c1X1+b,
0"~i^
public String getSFilePath() "~TA SX_?
{ ?` SUQm
return sFilePath; XMG]Wf^%\<
} \uss Uv
)M2F4[vcb
;Eu3[[V
public void setSFilePath(String value) R_=6GZH$G
{ zB yqD$
sFilePath = value; -i-?.:
} Z{'i F
tTd\|
X.`~>`8
public String getSFileName() !3T&4t
{ fM^[7;]7e
return sFileName; #^+DL]*l
} "RIZV
fNGZo
HR}bbsqxVf
public void setSFileName(String value) pW4 cX
{ YBh'EL}P
sFileName = value; 9@+5LZR
} 8,dBl!G=
O12eH
g+X}c/".
public int getNSplitter() |7x\m t
{ yA47"R
return nSplitter; 2wF8 P)
} vv26I
"Ks,kSEzu
:1Sl"?xU
public void setNSplitter(int nCount) ON+J>$[[
{ jt+iv*2N>
nSplitter = nCount; )>BHL3@
} $.]l!cmi%Q
} XrZ*1V
V)}rEX
v%Wx4v@%SE
/* ,AT[@
**Utility.java (p%>j0<
*/ A_KW(;50
package NetFox; >M&3Y XC
](|\whI
0Won9P
public class Utility { 3Gkv4,w<
k5]j.V2f
nT2)E&U6%
public Utility() _UuC,Pl3
{ qx%}knB
Hc`A3SMR
Bj7gQ%>H4
} irjP>3_e
m#=z7.XrX
//线程睡眠 dO%W+K
public static void sleep(int nSecond) 7 [0L9\xm
{ sJNFFOz
try{ $ MC)}l
Thread.sleep(nSecond); 5atYOep
} 8_N]e'WUh
catch(Exception e) .1LCXW=
{ $8BPlqBIZ
e.printStackTrace (); i~r l o^
} z;y:9l
} 3po:xMY
|fo0
//日志 5eWwgA
public static void log(String sMsg) }l=xiAF
{ XC+A_"w)
System.err.println(sMsg); S{3nM<
} JfPD}w
-IV]U*4
++E3]X|
public static void log(int sMsg) Z@r.pRr'
{ 6^DR0sO
System.err.println(sMsg); m4*@o?Ow
} q:g2Zc'Y~W
} f7}*X|_Y
Dl}$pN
O+ICol
/* t%8d-+$
**TestMethod.java j1(D]Z=\
*/ C`q@X(_
package NetFox; ?Q&yEGm(
_Zr.ba
b".L_Ma1*
public class TestMethod { rXHv`ky
N?.%?0l
9+pmS#>_
public TestMethod() IH"6? 9nd
{ ///xx/weblogic60b2_win.exe Nv"EV;$
try{ )RcL/n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]~3U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `He,p -
SiteFileFetch fileFetch = new SiteFileFetch(bean); $cZUM}@
fileFetch.start(); +sJrllrE(
} zen*PeIrA^
catch(Exception e){e.printStackTrace ();} [ Fz`D/
4!wR_@W^El
MuSUKBhM
} M %Qt|@O
E6WA}_
S.a%
public static void main(String[] args) XO'l Nb.
{ .rf" (lM
new TestMethod(); y8DhOlewQ
} ZIF49`Y4TF
} }[xs~!2F
点击下载更多相关资料