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)); vLyazVj..
} B&0W P5OF
for(int i=0;i<nEndPos.length-1;i++) 5Z5x\CcC3
{ <V Rb
nEndPos = nStartPos[i+1]; .>P:{''
} QG2 Zh9R
nEndPos[nEndPos.length-1] = nFileLength; HEIg_6sb
} cC+2%q B
} `|nCnT'
Pd(_
tMp!MQ
//启动子线程 7')W+`o8eL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,]W|"NUI
for(int i=0;i<nStartPos.length;i++) G -+!h4p
{ =WBfaxL}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TsGx2[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x\f~Gtt7Y
nStartPos,nEndPos,i); u*rP8GuS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '[%#70*
fileSplitterFetch.start(); js@L%1r#L
} 6Io}3}3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L/`1K_\l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w D r/T3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :zLf~W
nEndPos = " + nFileLength); T<?kH
// fileSplitterFetch[nPos.length-1].start(); FO:L+&hr?>
^\?Rh(pu
.g\Oj0Cbxh
//等待子线程结束 K,,) FM
//int count = 0; w}zmcO:x
//是否结束while循环 k0K$OX*:e
boolean breakWhile = false; p'1/J:EnV
M*kE |q/K
0doJF@H
while(!bStop) UeLO`Ug0;
{ q!@!eC[b
write_nPos(); ZH9Fs'c=
Utility.sleep(500); J{Kw@_ypP
breakWhile = true; ZDgT"53
^-[ I;P
=CZRX' +yN
for(int i=0;i<nStartPos.length;i++) UU MB"3e
{ j-W$)c3X
if(!fileSplitterFetch.bDownOver) `Hlf.>b1
{ dnU-v7k,{
breakWhile = false; J:Qx5;b;
break; /Xb4'Qj
} }&e HU
} C49\'1\6
if(breakWhile) X.k8w\~
break; ce}A!v
}6/M5zF3
H>+])~#
//count++; /pPHD]
//if(count>4) PQ[?zNrSV
// siteStop(); F}ATY!
} )`f-qTe
hRu}P"
6AG]7d<
System.err.println("文件下载结束！"); UGy3B)
} to</
catch(Exception e){e.printStackTrace ();} 0#!}s&j/
} Y6VJr+Ap(
x]x3iFD
L'?aoRj
//获得文件长度 4oiE@y&{4
public long getFileSize() `cXLa=B)9
{ >RkaFcq
int nFileLength = -1; t~/:St
try{ ":M]3.
URL url = new URL(siteInfoBean.getSSiteURL()); -oyA5Yx0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rSJ!vQo Cb
httpConnection.setRequestProperty("User-Agent","NetFox"); t:fz%IOe
fI<LxU_n:
O8A1200
int responseCode=httpConnection.getResponseCode(); f(D'qV T{
if(responseCode>=400) $) "\N
{ RBn/7
processErrorCode(responseCode); e,_Sj(R8
return -2; //-2 represent access is error 0lg'QG>
} 4J_HcatOB
`y.4FA4"8
*u"%hXR
String sHeader; K6p\ >J
nsU7cLf"^V
B?=R= p
for(int i=1;;i++) F{E@snc
{ 1bCE~,tD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !6=;dX
//Utility.log(in.readLine()); t8EI"|
sHeader=httpConnection.getHeaderFieldKey(i); DX>LB$dy?
if(sHeader!=null) S W%>8
{ -@"3`uv"
if(sHeader.equals("Content-Length")) [+dCA
{ O@a OKk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~Dq-q6-@t
break; q| 1%G Nb
} Q!@M/@-Ky
} E2>{seZ
else K?'m#}]
break; )2?]c
} zMbFh_dcq
} sPvs}}Z]P
catch(IOException e){e.printStackTrace ();} MLHCBRi
catch(Exception e){e.printStackTrace ();} Cy$~H
bTimJp[b
C`i#7zsH
Utility.log(nFileLength); =|1_6.tz
O|8@cO
@u9L+*F
return nFileLength; ?5nEmG|kO
} ?DUim1KG
HZRFE[ 9nb
L?N&kzA
//保存下载信息（文件指针位置） aj;x:UqpJ
private void write_nPos() oLKliA=q
{ ?YL JXq
try{ B.5+!z&7
output = new DataOutputStream(new FileOutputStream(tmpFile)); e3SnC:OWf
output.writeInt(nStartPos.length); Az:~|P
for(int i=0;i<nStartPos.length;i++) %lnkD5
{ yM@sGz6c!
// output.writeLong(nPos); {im?tZ,
output.writeLong(fileSplitterFetch.nStartPos); giNXXjl
output.writeLong(fileSplitterFetch.nEndPos); &!X<F,
} HAK,z0/
output.close(); ^t4^gcoZ4Z
} f)T\
catch(IOException e){e.printStackTrace ();} >o1dc*
catch(Exception e){e.printStackTrace ();} @`L;_S+
} V*\hGNV
S}JOS}\^j
l}L81t7f
//读取保存的下载信息（文件指针位置） aH1CX<3)~
private void read_nPos() z)C/U
{ md+pS"8o;
try{ yor'"6)i
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <jV,VKL#
int nCount = input.readInt(); QNx]8r
nStartPos = new long[nCount]; }qECpKa0
nEndPos = new long[nCount]; '9f0UtT|[
for(int i=0;i<nStartPos.length;i++) n<8WjrK
{ K{DC{yLu
nStartPos = input.readLong(); !lNyoX/
nEndPos = input.readLong(); qK.(wFx
} 0QZT<Zs
input.close(); X|{Tljn
} )]C]KB
catch(IOException e){e.printStackTrace ();} rk1,LsZVS
catch(Exception e){e.printStackTrace ();} #E!^oZm<Z
} #b[bgxm
R*:$^v@4
VNWB$mM.2
private void processErrorCode(int nErrorCode) JGHj(0j
{ S3%2T
System.err.println("Error Code : " + nErrorCode); gd0)s1{9
} 9$HKP9G
h<%$?h+}
4u}Cki,vOK
//停止文件下载 =_-u;w1D
public void siteStop() 2QaE&8vW
{ ~_EDJp1J
bStop = true; y`n?f|nf
for(int i=0;i<nStartPos.length;i++) o:QL%J{[
fileSplitterFetch.splitterStop(); vz4( k/
B.G6vx4yp
L&kCI`Tb
} D^@@ P
} D{B?2}X
//负责部分文件的抓取 ]4H)GWHKg
**FileSplitterFetch.java _|M8xI
*/ \o[][R#D
package NetFox; c_vGr55
,A`|jF
EF :g0$
import java.io.*; !j'LZ7
import java.net.*; 5T#v&
9DA|;|
P'8RaO&d
public class FileSplitterFetch extends Thread { A^z{n/DiL
Py v>
v>`Fo[c
String sURL; //File URL 4O-LLH
long nStartPos; //File Snippet Start Position [Kc?<3W
long nEndPos; //File Snippet End Position j<kW+Iio
int nThreadID; //Thread's ID Am*IC?@tq
boolean bDownOver = false; //Downing is over B%\&Q@X
boolean bStop = false; //Stop identical _\\Al v.
FileAccessI fileAccessI = null; //File Access interface ]\^O(BzB
ir}z^+
Y_[7q<L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %mmV#vwp
{ .hx(9
this.sURL = sURL; E\/[hT
this.nStartPos = nStart; ^o5;><S]
this.nEndPos = nEnd; rB".!b
nThreadID = id; 1+*sEIC"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 i+O7,"(@
} 'l5
HU>>\t?d
1@OpvO5
public void run() ^(:~8 h
{ [voZ=+/
while(nStartPos < nEndPos && !bStop) Q$5t~*$`
{ q~> +x?30
eAW)|=2
a9e0lW:=c
try{ :8@)W<>%
URL url = new URL(sURL); [Ep'm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v Z]j%c@
httpConnection.setRequestProperty("User-Agent","NetFox"); [mv? \HDa~
String sProperty = "bytes="+nStartPos+"-"; ;av!fK
httpConnection.setRequestProperty("RANGE",sProperty); CqEbQ>?
Utility.log(sProperty); H]tD~KM<
D'!JV1Q
t>"`rcg
InputStream input = httpConnection.getInputStream(); $CMye; yL
//logResponseHead(httpConnection); PMTrG78p*
Mbxl{M >
hiVa\s
byte[] b = new byte[1024]; T9$~tv,5F
int nRead; [w<_Wj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) f@;pN=PS
{ lUjZ=3"'
nStartPos += fileAccessI.write(b,0,nRead); 2gO@
//if(nThreadID == 1) IoOOS5a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )]q Qgc&
} ]8%E'd
1_{e*=/y
6Tmz!E0
Utility.log("Thread " + nThreadID + " is over!"); 3?j:M]fR
bDownOver = true; ,Gv}N&
//nPos = fileAccessI.write (b,0,nRead); ?n{m2.H
} 2 )o2d^^
catch(Exception e){e.printStackTrace ();} h^rG5Q
} {,5.svO
} KH#z=_
U<&=pv
_5S0A0
//打印回应的头信息 KC}G_"f.$
public void logResponseHead(HttpURLConnection con) gnZ#86sO
{ J=Kv-@I>E
for(int i=1;;i++) 6rbR0dSgx
{ %pjY^tM/
String header=con.getHeaderFieldKey(i); @,oc%m
if(header!=null) 3q`f|r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MD$W;rk(Hn
Utility.log(header+" : "+con.getHeaderField(header)); Pteti
else sT1k]duT
break; ;R0LJApey
} B ZU@W%E
} +)yoQRekX
[nHN@p|
B~}BDnu6
public void splitterStop() M{orw;1Isy
{ O-7)"
bStop = true; TI8\qIW
} 5yt=~
i Ehc<
j7E;\AZ^
} vKW!;U9~P
k(Xs&f `
^|oI^"IQ=
/* rr,A Vw
**FileAccess.java .s4vJKK0
*//文件访问(定位，写) ;/V])4=
package NetFox; FWeUZI+
import java.io.*; ~m<K5K6 V
(t3gNin
*PlKl_nP6
public class FileAccessI implements Serializable{ :j~4mb?$
JcYY*p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #QsJr_=
RandomAccessFile oSavedFile; Hc8^w6S1@
long nPos; u= dj3q
&bJBsd@Os
R%r25_8
public FileAccessI() throws IOException Q*Jb0f
{ 5-0&`,
this("",0); fcp_<2KH
} .n_Z0&i/w
I-8I/RRkmP
#*9 |\
public FileAccessI(String sName,long nPos) throws IOException 'wFhfZB1!B
{ ?4wl
oSavedFile = new RandomAccessFile(sName,"rw"); `0%;Gz%}
this.nPos = nPos; 7./WS,49
oSavedFile.seek(nPos); XBX`L"0
} ?99r>01>
[bKc5qp
@?J7=}bzz
public synchronized int write(byte[] b,int nStart,int nLen) kK4+K74B
{ ZYY~A_C
int n = -1; @VHstjos^V
try{ 0VQBm^$(
oSavedFile.write(b,nStart,nLen); Iu0GOy*[
n = nLen; Zc38ht\r;
} 7)}_'p
catch(IOException e) j*gZvbO;'L
{ %I`'it2d
e.printStackTrace (); m["e7>9G
} ;uc3_J]
?#<'w(^%#
\H>Psv{
return n; MV3K'<Y
} #]^C(qmb:
~G8l1dD
s+_8U}R
} z|],s]F>G
-]}#Z:&
lmUCrs37
/* 5`&@3 m9/
**SiteInfoBean.java 4`o0?_.'
*/ vq9O|E3
package NetFox; ~C>;0a;<:
`K@N\VM
lxZ9y
public class SiteInfoBean { {4SaSv^/
z^*g2J,
@N[<<k7g
private String sSiteURL; //Site's URL P()n=&XO6
private String sFilePath; //Saved File's Path L$"x*2[A
private String sFileName; //Saved File's Name %&H^UxC
private int nSplitter; //Count of Splited Downloading File BZTj>yd
@\gE{;a8
6)=;cc{Vr
public SiteInfoBean() 6NyUGGRq
{//nSplitter的缺省值为5 O%bltNEx1
//default value of nSplitter is 5 NMg(tmh
this("","","",5); nfZe"|d
} ^h=gaNL
GNwFB)?j
/EQ^-4yr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !"/"Mqs3$
{ 8z|]{XW{
sSiteURL= sURL; OcpvY~"Pr
sFilePath = sPath; 4_2oDcdf
sFileName = sName; {C?$osrr
this.nSplitter = nSpiltter; jC:D>
N0$ uB"
z*b|N45O
} p]~PyzG!
-f:PgBj
GHLFn~z@XJ
public String getSSiteURL() sAA;d
{ $z)egh(z
return sSiteURL; >(YH@Z&;
} t]vv&vk>
Je"XIhBr
:qR8 e J
public void setSSiteURL(String value) dR>$vbjh1Z
{ gyy}-^`F
sSiteURL = value; 9' H\-
} W:WRG8(F
3 %r*~#nz
<WmjjD
public String getSFilePath() .MDSP/s
{ ['>r tV
return sFilePath; Zs0;92WL
} pwSkwJ]
{#@[ttw$U
~z41$~/
public void setSFilePath(String value) 1S+T:n
{ rK;<-RE<[:
sFilePath = value; RxPD44jVA
} Rm,>6bQx
ghkV^ [
h?ijZHG $
public String getSFileName() Je^;[^
{ &F;bg
return sFileName; n^55G>"0|
} {fEb>
j~+(#|
[*C~BM
public void setSFileName(String value) |z@AvS[
{ Y)(w&E>1
sFileName = value; -!T24/l
} nnu#rtvZp}
6&LmR75C
XdlA)0S)
public int getNSplitter() |Q%nnN
{ f/.f08
return nSplitter; !)J$f_88D
} )"tM[~e`
2}.~ 6EU/
U? U3?Y-k`
public void setNSplitter(int nCount) X g7xy>{]
{ <?;KF2A({
nSplitter = nCount; PRyzvc~
} VggSDb
} J5f}-W@
KxhWZ3
UpQda`rb
/* cV`NQt<W
**Utility.java Y>2#9LA
*/ \SgBI/L^
package NetFox; U: <
\7o7~pll
>G[:Q s
public class Utility { %\'G2
l]
X*Q<REDB
public Utility() u Vv%k5
{ G_k_qP^:
z-]ND
vQoZk,
} 7a/ BS(kq<
o~xGE6A*"
//线程睡眠 d,'gh4C
public static void sleep(int nSecond) 4] u\5K-
{ jQfnc:'
try{ NSzTl-eS
Thread.sleep(nSecond); ]R09-s 0$7
} 3:OqD~,zy
catch(Exception e) ka`}lR
{ p~(STHDe#
e.printStackTrace (); `oO*ORq&
} Ak}`zIo
} -\Z`+kY?p
Qo(<>d
//日志 -Vmp6XY3q
public static void log(String sMsg) ,x3<a}J
{ VYH $em6
System.err.println(sMsg); :yw(Co]f
} -0k{O@l"
4zOFu/l6R
UQb|J9HY4
public static void log(int sMsg) :8v? 6Q
{ 4 4WyfpTJ*
System.err.println(sMsg); NUtKT~V
} \ZSqZDq
} %_39Wa
['6Sq@c)
NUuIhB+
/* M,r8 No
**TestMethod.java u@Z6)r'
*/ SapVS*yx@
package NetFox; Cs vwc%
X7?14W
-2C^M> HZ
public class TestMethod { r"VNq&v]9
gla'urb[i|
0@ vzQ$
public TestMethod() !bX
{ ///xx/weblogic60b2_win.exe tI.ho
try{ |*8X80<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u&f|z9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %Go/\g
SiteFileFetch fileFetch = new SiteFileFetch(bean); ],zp~yVU&
fileFetch.start(); AJoP3Zv|?
} A=D G+z''
catch(Exception e){e.printStackTrace ();} SK@lr
}n,LvA@[0
1:{+{Yl7
} ZlQ&m
jS#YqVuN
bc& 5*?
public static void main(String[] args) W:8{}Iu<
{ zTn.#-7y
new TestMethod(); --vJR/-
} +5:9?&lH
} wjKc!iB
点击下载更多相关资料