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)); - 5o<Q'(
} k}I5x1>&
for(int i=0;i<nEndPos.length-1;i++) mI?* Z%>g
{ 7}#*3*]
nEndPos = nStartPos[i+1]; y?*[}S
} W>q*.9}Y"
nEndPos[nEndPos.length-1] = nFileLength; 5I)~4.U|,m
} U+9-li
} j1;_w
?O<`h~'$+
cYq']$]
//启动子线程 vR%j#v|s
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]5o0
for(int i=0;i<nStartPos.length;i++) _A;vSp.`
{ eN<>#:`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7,W]zKH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;<bj{#mMv
nStartPos,nEndPos,i); "o^bN 9=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nl)_`8=
fileSplitterFetch.start(); "q9~C
} WIEx '{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a%MzNH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @O}IrC!bf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $tDCS
nEndPos = " + nFileLength); vDK:v$g
// fileSplitterFetch[nPos.length-1].start(); ;Ch+X$m9
=2.tu*!C
zJnL<Q
//等待子线程结束 )d770Xg+
//int count = 0; 1EC-e|M.
//是否结束while循环 `uIx/.L
boolean breakWhile = false; Qfkh0DX B
(aDb^(]>
>0Fxyv8
while(!bStop) |dl0B26x
{ "t(1tWO1o
write_nPos(); !F0rd9
Utility.sleep(500); _KSfP7VU
breakWhile = true; A6?qIy
BB2_J=wA
njy~
for(int i=0;i<nStartPos.length;i++) >zPO>.?h7T
{ K;<NBnH
if(!fileSplitterFetch.bDownOver) >u9id>+
{ Ax5mP8S
breakWhile = false; O3^98n2
break; N5q}::Odc
} u"`5
} {\vI9cni|"
if(breakWhile) :DOr!PNA
break; o9KyAP$2
bc3|;O
[+hy_Nc$
//count++; Ij;==f~G
//if(count>4) x !#Ma
// siteStop(); ]k[Q]:q
} 8BYIxHHz
.DgoOo%?"
cPA~eZbX
System.err.println("文件下载结束！"); 7.wR"1p#
} wFK:Dp_^
catch(Exception e){e.printStackTrace ();} Q `e~MD
} bn0"M+7)f
`FZ(#GDF
i&A{L}eCr:
//获得文件长度 |Hx%f
public long getFileSize() K(-G: |
{ 5xh!f%6
int nFileLength = -1; 52>[d3I3
try{ G"G{AS
URL url = new URL(siteInfoBean.getSSiteURL()); =]=B}L`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -rEeKt
httpConnection.setRequestProperty("User-Agent","NetFox"); %iK%$
R<0Fy=z
e%PCe9
int responseCode=httpConnection.getResponseCode(); @PYW|*VS
if(responseCode>=400) [GtcaX{Zz
{ #^5a\XJb
processErrorCode(responseCode); *e(:["v
return -2; //-2 represent access is error Dl0/-=L
} NzjMk4t
5Waw?1GL
9k+N3vA
String sHeader; 8# 6\+R
' oBo|
]WTf< W<
for(int i=1;;i++) ]O6KKz
{ x7vq?fP0n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XxmJP5
//Utility.log(in.readLine()); "nVK< Vd
sHeader=httpConnection.getHeaderFieldKey(i); K5P Gi#
if(sHeader!=null) +n@f'a">
{ JzHqNUn*M
if(sHeader.equals("Content-Length")) Z1VC5*K
{ " <<A
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7sj<|g<h(_
break; U5|B9%:&
} G1kDM.L
} l<u{6o
else }16&1@8
break; l*$WX=h6n
} ?g5iok {
} 4BHtR017r
catch(IOException e){e.printStackTrace ();} a`DWpc~
catch(Exception e){e.printStackTrace ();} \M+MDT&
gdOe)il\
0LS-i%0
Utility.log(nFileLength); N2ni3M5v
%,33gZzf
E|Q{]&$;Z"
return nFileLength; S <2}8D
} AnRlH
qpoquWZ
- o4@#p>>
//保存下载信息（文件指针位置） \^Ep>Pq`]
private void write_nPos() 9X!ET!
{ $2Kau 1
try{ iwvt%7
output = new DataOutputStream(new FileOutputStream(tmpFile)); Vre=%bGw
output.writeInt(nStartPos.length); dAL0.>|`0
for(int i=0;i<nStartPos.length;i++) (RExV?:
{ P=c?QYF
// output.writeLong(nPos); L{!ihJr
output.writeLong(fileSplitterFetch.nStartPos); :lNg:r$4
output.writeLong(fileSplitterFetch.nEndPos); X2i*iW<
} YdK_.t0Mu
output.close(); T0;u+$
} p Z"o@';!
catch(IOException e){e.printStackTrace ();} nlaG<L#
catch(Exception e){e.printStackTrace ();} |Mt&p#y
} \xF;{}v
{z=j_;<]
Ah*wQow
//读取保存的下载信息（文件指针位置） w %;hl#s
private void read_nPos() yDzdE;
{ S)+CTVVE
try{ tL1P<1j_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vuXS/ d
int nCount = input.readInt(); HF]EU!OT
nStartPos = new long[nCount]; p7s@%scp
nEndPos = new long[nCount]; >o#ERNf
for(int i=0;i<nStartPos.length;i++) ~xw5\Y^
{ ,`yyR:F
nStartPos = input.readLong(); 4b]_ #7Qm
nEndPos = input.readLong(); Yhe+u\vGs\
} "2%>M
input.close(); 6eM6[
} #^Ys{
catch(IOException e){e.printStackTrace ();} ^/k,
catch(Exception e){e.printStackTrace ();} z9 O~W5-U
} ,6DD=w0r
}~rcrm.
/oFc03d
private void processErrorCode(int nErrorCode) vmvFBzLR
{ `v~!H\q
System.err.println("Error Code : " + nErrorCode); $Y6 3!*
} V`by*s
#XcU{5Qm5
WK*S4c
//停止文件下载 R+d< fe
public void siteStop() w(Gz({l+
{ kymn)Ea
bStop = true; aV<^IxE;
for(int i=0;i<nStartPos.length;i++) xHHV=M2l(s
fileSplitterFetch.splitterStop(); V`[P4k+b
`os8;`G
{8 N=WZ
} x)3~il5
} DKTD Z*
//负责部分文件的抓取 _|X7 n~
**FileSplitterFetch.java 7lwTZ*rnY
*/ , |l@j%
package NetFox; IfMpY;ow=
x~EKGoz3
Z["BgEJ
import java.io.*; Sl"BK0:%7
import java.net.*; ;T>+,
0yz~W(tsm
&+G;R
public class FileSplitterFetch extends Thread { 'y.JcS!|
W^k,Pmopy
MxTmWsaW
String sURL; //File URL :Jk33 N4y0
long nStartPos; //File Snippet Start Position 4%J|DcY2
long nEndPos; //File Snippet End Position T9?54r
int nThreadID; //Thread's ID w4,]2Ccn.
boolean bDownOver = false; //Downing is over L,$3Yj
boolean bStop = false; //Stop identical Oc~aW3*A(
FileAccessI fileAccessI = null; //File Access interface NI.`mc6Xd
4-V)_U#8
W$'0Dc
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _=EZ `!%
{ M|8 3HTJ
this.sURL = sURL; +xp*]a
this.nStartPos = nStart; ! Mo`^t
this.nEndPos = nEnd; 8teJ*sz
nThreadID = id; aMJ;bQD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )7Ixz1I9g
} ,{8v4b-
bi$VAYn.^
Ly>OLI0x_
public void run() H\#:,s{1
{ H^ BYd%-
while(nStartPos < nEndPos && !bStop) OH6n^WKY
{ NXI[q'y
utH%y\NMF|
,E}$[mHyjz
try{ "!KpXBc,>
URL url = new URL(sURL); V!&P(YO:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {/|qjkT&W
httpConnection.setRequestProperty("User-Agent","NetFox"); eFFc9'o
String sProperty = "bytes="+nStartPos+"-"; 6Dst;:
httpConnection.setRequestProperty("RANGE",sProperty); r~>,$[|n})
Utility.log(sProperty); 'N6 S}w7
S4bBafj[I
%4,?kh``D
InputStream input = httpConnection.getInputStream(); m|F:b}0Hb
//logResponseHead(httpConnection); wz=z?AZW
HnU Et/
,@.EpbB
byte[] b = new byte[1024]; VLdB_r3lQ
int nRead; IzUo0D*@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &{z<kmc$6
{ P^i.La,
nStartPos += fileAccessI.write(b,0,nRead); ,S!w'0k|n
//if(nThreadID == 1) Cj^{9'0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hO( RZ'{
} ;LMWNy4
;`UecLb#
rMp9jG@3
Utility.log("Thread " + nThreadID + " is over!"); |[1D$Qv
bDownOver = true; Lh ap4:
//nPos = fileAccessI.write (b,0,nRead); 2"&)W dm
} Nfn(Xn*J-
catch(Exception e){e.printStackTrace ();} :2y"3azxk
} >|*yh~
} _^\$"nw
#/ "+
|W7rr1]~S
//打印回应的头信息 b$-e\XB!
public void logResponseHead(HttpURLConnection con) &`Ck
{ yI)~]K r
for(int i=1;;i++) Xy7Z38G
{ o6L9UdT
String header=con.getHeaderFieldKey(i); >/^#Drwb!i
if(header!=null) IIz0m3';+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9[Qd)%MO
Utility.log(header+" : "+con.getHeaderField(header)); %*W<vu>H
else ^gYD*K!*
break; ^p=L\SJ
} @i%YNI5*
} c`G&KCw)d
Q@QFV~
uk7'K 0j
public void splitterStop() '&yeQ
{ sl|_=oXT
bStop = true; glUo7^ay7
} ,)fkr]`<
,k0r
!GK$[9
} .$rC0<G[K
vqNsZ 8|`
~;#MpG;e
/* |$+5@+Zz
**FileAccess.java Re=WfG
*//文件访问(定位，写) *"{&FEV
package NetFox; K_BPZ5w
import java.io.*; .tXtcf/
7^:4A'
Nt-<W+,
public class FileAccessI implements Serializable{ , c;eN
SUtf[6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6Y384
RandomAccessFile oSavedFile; lWZuXb,G
long nPos; fI|[Z+"
5g ;ac~g
wts:65~
public FileAccessI() throws IOException ;%!m<S|%k
{ _|{aC1Y!V
this("",0); e [0w5)X
} LMl~yqM
,LYFEq_
2WBq
public FileAccessI(String sName,long nPos) throws IOException @R2at
{ M8;lLcgu.
oSavedFile = new RandomAccessFile(sName,"rw"); =U-r*sGLN
this.nPos = nPos; UWXm?v2j
oSavedFile.seek(nPos); ,"?A2n-qO
} 9IZu$-
w YNloU
^4$'KIq
public synchronized int write(byte[] b,int nStart,int nLen) n&XGBwgW
{ =hH.zrI6e
int n = -1; {padD p
try{ +|RB0}hFS-
oSavedFile.write(b,nStart,nLen); u\e\'\
n = nLen; 1cJsj
} -V<t-}h.
catch(IOException e) fP-|+TyO
{ ' [0AHM
e.printStackTrace (); +V(5w`qx
} )9j06(<A
peVq+(=.
K`KLC.j
return n; x^=M6;:
} '3(l-nPiG^
Jobiq]|>
Z@rN_WXx
} f"5g>[1
*TdnB'Gd
ra7uU*
/* j) vlM+
**SiteInfoBean.java N=1JhjVk"
*/ rXi uwz\
package NetFox; A2H4k|8
O9h+Q\0\W
9h,u6e
public class SiteInfoBean { Xh+ia#K
J{"kw1Lu
sKaE-sbJY
private String sSiteURL; //Site's URL u=+q$Q]
private String sFilePath; //Saved File's Path keAcKhj
private String sFileName; //Saved File's Name ]gb=
private int nSplitter; //Count of Splited Downloading File f<jb=\}x
q 2?X"!
vR7HF*8
public SiteInfoBean() m>&HuHf
{//nSplitter的缺省值为5 kAzd8nJ'
//default value of nSplitter is 5 j8,n7!G
this("","","",5); `(4pu6uT
} F1azZ(
7Hw<ojkt
-#&kYK#Ph
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p#d+>7
{ xBnbF[
sSiteURL= sURL; 5ua?I9fY
sFilePath = sPath; 'C+;r?1!h
sFileName = sName; {==pZpyyh
this.nSplitter = nSpiltter; !UBO_X%dz
8Z#j7)G
nY?
} x<(b|2qf
\&xl{64
[pOg'
public String getSSiteURL() /L=(^k=a.;
{ 5t:8.%<UK
return sSiteURL; !%L,*'
} v@ C,RP9
]n1dp2aH
jh ez
public void setSSiteURL(String value) Y#V8(DTyH
{ CX/(o]
sSiteURL = value; pR os{Uq"
} #~ v4caNx
`d]Z)*9
#} ,x @]p
public String getSFilePath() X~T/qFS
{ _cqy`p@"
return sFilePath; &vUq}r%P
} ,i}|5ozj4
|cbd6e{!
H-t|i
public void setSFilePath(String value) ~9o6 W",
{ ('k<XOi
sFilePath = value; E$\~lcq
} f_mhD dq
R'K/t|MC
w_-+o^
public String getSFileName() >wON\N0V_
{ uGtV}-t:
return sFileName; L&2u[ml
} C*~aSl7
_kraMQ>
\{|ImCH
public void setSFileName(String value) TRvZ
{ d.F)9h]XHO
sFileName = value; dbGgD=}o
} $^%N U
v"6 \=@
|Fln8wB
public int getNSplitter() #;r]/)>
{ v|t{1[C
return nSplitter; eD#XDK
} 70gg4BS
i?}>.$j
dSK0h(8
public void setNSplitter(int nCount) H[&@}v,L
{ QJX/7RA
nSplitter = nCount; S3\jcgrS
} F1W+o?B
} e<+<lj"
:h5J r8
h[Tk;h
/* 5G*II_j
**Utility.java 5~VosUpe7
*/ a5c'V
package NetFox; K b(9)Re
|ng%PQq)
'1+.t$"/tU
public class Utility { Bq}x9C&<
=Viy^ieN$
EA0iYzV
public Utility() wK5_t[[
{ &"S/Lt
zQfkMa.
Ol+Kp!ocY
} 4<gJ2a3
Z7#7N wy4
//线程睡眠 *g7DPN$aQ
public static void sleep(int nSecond) vOT*iax0
{ Da,Tav%b
try{ >;lKLGJrd>
Thread.sleep(nSecond); _/x&<,3
} bx;f`8SN
catch(Exception e) GW m4~]0E
{ 3N%{B
e.printStackTrace (); qo;)X0N
} Ye|G44z
} aqL<v94wX
"'{OIP
//日志 &HF]\`RNr
public static void log(String sMsg) L|67f4
{ gxM[V>[
System.err.println(sMsg); OlGR<X
} $KQ,}I
kK?zVH-!
H@W0gK(cS;
public static void log(int sMsg) |5ONFde"0
{ DrS?=C@
System.err.println(sMsg); *zQOJsg"e
} In(NF#
} CA^.?&CH^O
`]>on`n?
#"r kuDO
/* P9yw&A
**TestMethod.java -1mvhR~
*/ <%?uYCD
package NetFox; !R{em48D
HD00J]y_
;,`]O!G:P
public class TestMethod { 6Ct0hk4
{PmzkT}LF
ZR mPP
public TestMethod() ?`i|"y#
{ ///xx/weblogic60b2_win.exe B1,?{Ur
try{ fLM.kCD?u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g RU-g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); s01$fFJgO
SiteFileFetch fileFetch = new SiteFileFetch(bean); 88YC0!Ni
fileFetch.start(); m)k-uWc$C
} 8bGD
catch(Exception e){e.printStackTrace ();} sH@ &*
.b~OMTHuvM
l#ygb|=x
} Xj;2h{#s
?\d5;%YSr
P2QRvn6v
public static void main(String[] args) "c EvFY
{ w3d\0ub
new TestMethod(); X&,N}9>B
} 8E-Ip>{>
} Vy r] x
点击下载更多相关资料