http断点续传简单实现（java)

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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)); vn]e`O>y
} MY8[)<q"
for(int i=0;i<nEndPos.length-1;i++) <6 HrHw_
{ KI@OEy
nEndPos = nStartPos[i+1]; 4jOq.j
} 5Iql%~_x
nEndPos[nEndPos.length-1] = nFileLength; K}vP0O}
} DLigpid
} "Je*70LG#
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kM0TQX)$m
//启动子线程 Bb,l.w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3Kx&+
for(int i=0;i<nStartPos.length;i++) =bx;TV
{ TpB4VNi/<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #2/2Xv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 88@" +2
nStartPos,nEndPos,i); |ODi[~y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FZvh]ZX
fileSplitterFetch.start(); :7WeR0*%
} BHNcE*U}@?
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CAbeb+O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6T?$m7c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .T2P%Jn.
nEndPos = " + nFileLength); pR3@loFQ`o
// fileSplitterFetch[nPos.length-1].start(); >@Nn_d
m-<"`:+
X,]E {
//等待子线程结束 LU-,B?1
//int count = 0; c:J;Q){Xz
//是否结束while循环 ii3{HJ*C
boolean breakWhile = false; \ah.@s
A~@u#]]<n
{RmN1'%
while(!bStop) ;JD/4:
{ lYF~CNvE
write_nPos(); m@Q%)sc)
Utility.sleep(500); c%jW'
breakWhile = true; ezq<)gJc
/8Sr(
q':P9o*N?
for(int i=0;i<nStartPos.length;i++) =tKb7:KU
{ (GeOD V?U
if(!fileSplitterFetch.bDownOver) hxB` hu-
{ `kRv+Qwfa
breakWhile = false; Z\\'0yuY(
break; ^Fn~@'
} B24,;2J
} xJ);P.
if(breakWhile) @@1Sxv_
break; `|rr<Tsy\
[U^@Bkh
R5,ISD +s
//count++; ;Y^.SR"
//if(count>4) (}4]U=/nV
// siteStop(); h1(GzL%i_
} +o4W8f=Ga
fz[-pJ5[
\#hp,XV>
System.err.println("文件下载结束！"); [ r<0[
} C$<['D?8
catch(Exception e){e.printStackTrace ();} 1MPn{#Ff
} J"$Y`;
x1O]@Z{d\
S^,q{x*T
//获得文件长度 &gr)U3w
public long getFileSize() O>M4%p
{ e8Y;~OAj[
int nFileLength = -1; <hv {,1p-r
try{ aANzL
URL url = new URL(siteInfoBean.getSSiteURL()); !&f>,?wlP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (2l?~CaK
httpConnection.setRequestProperty("User-Agent","NetFox"); @hG]Gs[,o
OsGKlWM/
`{B<|W$=
int responseCode=httpConnection.getResponseCode(); W]-c`32~S
if(responseCode>=400) vJ a?5Jr
{ *#| lhf'
processErrorCode(responseCode); [b?[LK}.
return -2; //-2 represent access is error ?r%kif)
} :~ ; 48m
B.oD9<9
6+iZJgwAy
String sHeader; gz~)v\5D/
%8]~+#]p
&$x1^
for(int i=1;;i++) !D!1%@ e
{ ,WKWin
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9EU0R H
//Utility.log(in.readLine()); DOa%|H'P
sHeader=httpConnection.getHeaderFieldKey(i); ukAE7O(W&
if(sHeader!=null) :W6R]y
{ Ltrw)H}
if(sHeader.equals("Content-Length")) PX$_."WA
{ a^>e|Eq|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H7}@56
break; 6$y$ VeW
} .*,W%r?1n6
} )bkJ['9
else DZ*m"Bi
break; .271at#-
} p4sU:
} 7A6:*
catch(IOException e){e.printStackTrace ();} tDQo1,(oY
catch(Exception e){e.printStackTrace ();} z"PU`v
Vgg'5o&.
SU$%nK)
Utility.log(nFileLength); 7W7yjG3g
j +u3VP
O,Sqh$6U
return nFileLength; }%lk$g';
} !hc#il'g].
l(j._j~p
q Xj]O3 mm
//保存下载信息（文件指针位置） >713H!uj
private void write_nPos() 62Q`&n6
{ ~ ~U,
try{ l2ww3)Z
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y2&hf6BE
output.writeInt(nStartPos.length); } >zl
for(int i=0;i<nStartPos.length;i++) &f_ua)cyY
{ 6EY W:o
// output.writeLong(nPos); 11Y4oS
output.writeLong(fileSplitterFetch.nStartPos); s<b(@L 1
output.writeLong(fileSplitterFetch.nEndPos); 9_&N0>OF
} U3rpmml
output.close(); RGC DC*\
} L8.u7(-#
catch(IOException e){e.printStackTrace ();} zYZ^/7)
catch(Exception e){e.printStackTrace ();} ^3 6oqe{
} eZ`x[g%1
$:!L38[7$
0WO-+eRB/
//读取保存的下载信息（文件指针位置） %&\DCAFk
private void read_nPos() X6SqOb\(a
{ Z-;I,\Y%
try{ O[|prk,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i^_?C5
int nCount = input.readInt(); r(i!".Z
nStartPos = new long[nCount]; ?'%9
nEndPos = new long[nCount]; sNbCOTow
for(int i=0;i<nStartPos.length;i++) qV&ai{G:
{ YLkdT%
nStartPos = input.readLong(); y|h:{<
nEndPos = input.readLong(); vIpitbFC
} \ x>#bql+
input.close(); 227 Z6#CF!
} 3Jj 3!aDB
catch(IOException e){e.printStackTrace ();} ^oH!FN`;{
catch(Exception e){e.printStackTrace ();} Fb^f`UI
} k.K;7GZC
&:}}T=@M1
^QbaMX
private void processErrorCode(int nErrorCode) US2Tdmy@05
{ &?(472<f**
System.err.println("Error Code : " + nErrorCode); daN#6e4Z+;
} NU |vtD
[D= KI&@&O
GGF;4
//停止文件下载 F2WMts
public void siteStop() i8 fUzg)
{ +~l`rJ
bStop = true; @(I)]Ca%O
for(int i=0;i<nStartPos.length;i++) snti*e4"V
fileSplitterFetch.splitterStop(); fF.qQTy;7
}$D{YHF
kXY p.IVA
} ;UoXj+Z
} F?.J1]
//负责部分文件的抓取 g6l&;S40
**FileSplitterFetch.java OaCp3No
*/ eW.[M?,
package NetFox; {q^?Rw
wW1>#F
!dZpV~g0
import java.io.*; a/s6|ri`0
import java.net.*; ; +%|!~
O$$$1VHYo
NUb:5tL
public class FileSplitterFetch extends Thread { +8eW/Bs@2
0{zA6Xu
,W:Bh$%
String sURL; //File URL K.I\E
long nStartPos; //File Snippet Start Position e,rCutA)
long nEndPos; //File Snippet End Position QCVwslj,K
int nThreadID; //Thread's ID ppXt8G3%x
boolean bDownOver = false; //Downing is over w?Nx^)xX
boolean bStop = false; //Stop identical q@8j[15
FileAccessI fileAccessI = null; //File Access interface Yt#e[CYnu
," ~4l&
!Q" 3B6 86
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +t`QHvxv
{ W y%'<f
this.sURL = sURL; I$vM )+v=
this.nStartPos = nStart; 9<Kc9Z
this.nEndPos = nEnd; lL]8~3b
nThreadID = id; v.pj PBU1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }Pf7YuUZZ
} #M5[TN!
Tt*n.HA
o:C],G_
public void run() DX)T}V&mP
{ Z2soy-
while(nStartPos < nEndPos && !bStop) 7\p<k/TS
{ +'f38D*
'@ C\,E
pGhA
try{ 3t^r;b
URL url = new URL(sURL); L?~-<k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^"hsbk&Yu
httpConnection.setRequestProperty("User-Agent","NetFox"); "J(7fL$!
String sProperty = "bytes="+nStartPos+"-"; T.R(
httpConnection.setRequestProperty("RANGE",sProperty); j@b18wZ
Utility.log(sProperty); 2Y'=~*tV
d/3 k3HdL
8 ?+t+m[
InputStream input = httpConnection.getInputStream(); M+q|z0U
//logResponseHead(httpConnection); ~.'NG? %7P
1XvB,DhJ
#w<:H1,4
byte[] b = new byte[1024]; jf'#2-
int nRead; BoMf#l.3B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TRSR5D[
{ c7$U0JO
nStartPos += fileAccessI.write(b,0,nRead); )/1,Ogb%_
//if(nThreadID == 1) Z-BPC|e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;q6FdS
} B\z4o\am%
SOPQg?'n=V
%`Q<_LTU
Utility.log("Thread " + nThreadID + " is over!"); -A A='s
bDownOver = true; Axtf,x+lH
//nPos = fileAccessI.write (b,0,nRead); ,0=@cJ
} m+Bt9|d
catch(Exception e){e.printStackTrace ();} beM}({:`
} ]\Tcy[5
} U]h5Q.<SG
!ENb \'>J>
wZV/]jmlEt
//打印回应的头信息 jSyF]$"
public void logResponseHead(HttpURLConnection con) DMY?'Nts!
{ "jyh.@<
for(int i=1;;i++) 38hAguZX
{ Im\{b=vT
String header=con.getHeaderFieldKey(i); 8}0O @ wq
if(header!=null) jLEwFPz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Zg@NMT
Utility.log(header+" : "+con.getHeaderField(header)); M6+_Mi.
else h) .([
break; oU.LYz_
} 1Lf:TQB
} [|\JIr=of5
e2v[ma-
J}-,!3qxW
public void splitterStop() !a[1rQH
{ ]zza/O;31(
bStop = true; oKJj?%dHK9
} PB :Lj
e Ert_@}
K 8gd?88
} 5r:SBt|/
9OC!\' 8
27t23@{YL
/* 'RlPj0Cg
**FileAccess.java JKkR963 O
*//文件访问(定位，写) 54Baz
package NetFox; i7fQj, q
import java.io.*; +##b}?S%
<E(#;F^y
f3+@u2Pv
public class FileAccessI implements Serializable{ >!OD[9
XZv(B^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~7W?W<
RandomAccessFile oSavedFile; IQS:tL/
long nPos; T>&d/$;]
wnL\.%Y^
0wLu*K5$4E
public FileAccessI() throws IOException d (Fb_
{ 7J]tc1-re
this("",0); Yd4J:
} aMSX"N"ot
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n+M:0{Y|
public FileAccessI(String sName,long nPos) throws IOException .O{2]e$
{ Ocq.<#||H
oSavedFile = new RandomAccessFile(sName,"rw"); _(}{=:M?
this.nPos = nPos; DAG2pc8zA
oSavedFile.seek(nPos); 1@)8E`u
} C|"h]
gp:,DC?(
Y{TzN%|LV
public synchronized int write(byte[] b,int nStart,int nLen) m ?a&XZ
{ Uj)~>V'
int n = -1; &k /uR;yw
try{ XHgwK@GU
oSavedFile.write(b,nStart,nLen); y#:_K(A" k
n = nLen; krPwFp2[*
} )QGj\2I
catch(IOException e) c|lo%[]R!
{ ;/fZh:V2
e.printStackTrace (); GNzkVy:u
} yVvO!
[a;U'v*
J~6+zBF
return n; OAMsqeWYA
} ,~-"EQT
#YM5P
bb#F2r4
} hHsCr@i
\ %Er%yv)
{(@M0?
/* X !g"D6'
**SiteInfoBean.java 1D03Nbh|5
*/ \`\& G-\
package NetFox; +_tK \MN
.eAN`-t;
|1zoT|}q
public class SiteInfoBean { `Ym7XF&
sr+* q6W
Q# w`ZQX3
private String sSiteURL; //Site's URL _-$"F>
private String sFilePath; //Saved File's Path lCBb0k2
private String sFileName; //Saved File's Name cF9bSY_Eh
private int nSplitter; //Count of Splited Downloading File Xm./XC
P08=?
+1R?R9^Fw
public SiteInfoBean() pe>R2<!$
{//nSplitter的缺省值为5 =EI>@Y"
//default value of nSplitter is 5 V(mz||'*
this("","","",5); (+d7cln
} +85i;gO5
=m.Lw
FUic7>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =T'N6x5@
{ NGIbUH1[
sSiteURL= sURL; 0Ym+10g
sFilePath = sPath; `0Y`]kSY+
sFileName = sName; zdFO&YHTw
this.nSplitter = nSpiltter; ?El8:zt?|
_FXvJ}~m
f]MKNX
} )?#*GMWU
U}ei2q\
SFVOof#s
public String getSSiteURL() ~Rd,jfx
{ 3 f=_F
return sSiteURL; .UF](
} @:u>
"c8 -xG
T 22tZp
public void setSSiteURL(String value) FES_:?.0
{ v#1}( hb
sSiteURL = value; h+)XLs
} 'NyIy:
kR2kV"-l
pvdM3+6
public String getSFilePath() n qSjP5
{ ME"B1Se\
return sFilePath; n1+1/
} ?.tnaE
ru#,pJ=O(
xj8yQ Y1
public void setSFilePath(String value) Y5nj _xQJL
{ *->2$uWP
sFilePath = value; ]X y2km]
} \ng!qN
\1Tu P}P
2P3,\L
public String getSFileName() "Sm'TZx
{ iIT7pq1
return sFileName; ctI=|K
} @r7ekyO8)
cP#vzFB0>
h9<*+T
public void setSFileName(String value) /-%0y2"7
{ D d['e
sFileName = value; $gZC"~BR
} qiEw[3Za]'
.g/PWEr\I
8@b,>l$
public int getNSplitter() |^l17veA@
{ n hT%_se4
return nSplitter; mhh^kwW
} P/%5J3_,
ca )n*SD
-rg >y!L
public void setNSplitter(int nCount) 2F5*C
{ >6yA+?[:
nSplitter = nCount; i7rO5<
} p;#@#>h
} \ @XvEx%
B^|^hZZ>
`Vph=`0
/* CMu/n]?c
**Utility.java ckDWY<@v
*/ t`F<lOKj
package NetFox; >|j8j:S[
i|N%dl+T=
*vFXe_.
public class Utility { B\WIoz;'
\%],pZsA~
tW$Di*h
public Utility() dWKjVf
{ .VD:FFkW
9):h %o
oU|yBs1
} :8( "n1^
`^d[$IbDW
//线程睡眠 J}zN]|bz
public static void sleep(int nSecond) lftT55Tki
{ z5njblUz
try{ KOv?p@d
Thread.sleep(nSecond); @wVq%GG}
} vZ6_/ew8
catch(Exception e) Al93x
{ e-&0f);i
e.printStackTrace (); |.]g&m)y^h
} &];:uYmMU
} Fu%D2%V$/
i!yu%>:M
//日志 VbU*&{j
public static void log(String sMsg) Nbyc,a[o
{ xZ=6
System.err.println(sMsg); []L yu
} y [jck:
%f-Uwq&}Y"
{zNFp#z
public static void log(int sMsg) mMt~4(5
{ V;N'?Gu
System.err.println(sMsg); PR+L6DT_
} zWA~0l.2
} .&Ik(792Z&
?xTdL738
!C6[m1F
/* AQ<2 "s
**TestMethod.java @Jh;YDr`A
*/ ]DJ]L=T7
package NetFox; 5f}GV0=n
|V dr/'
k$d+w][
public class TestMethod { (@(rz/H
LX%UkfA9
6'a1]K
public TestMethod() yt5'2!jc
{ ///xx/weblogic60b2_win.exe e$Npo<u
try{ vyhxS.[9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &al\8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SbYsa
SiteFileFetch fileFetch = new SiteFileFetch(bean); zNh$d;(O$^
fileFetch.start(); .dw;b~p
} z~0f[As.
catch(Exception e){e.printStackTrace ();} }"\jB
&Jf67\N
\L5h&
} |M$ESj4@
w+Oo-AGNH
{8im{]8_
public static void main(String[] args) J_@`:l0,z
{ N*{>8iFo4
new TestMethod(); R64/m9
} D//uwom
} WoSJp5By$
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