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)); Xo(K*eIN
} &xr?yd
for(int i=0;i<nEndPos.length-1;i++) )Be}Ev#)Zx
{ 6h}f^eJ:K,
nEndPos = nStartPos[i+1]; : i3-7k
} LB? evewu
nEndPos[nEndPos.length-1] = nFileLength; T'\lntN
} (o{QSk\
} vb9G_Pfz
.zlUN0oe
; z:}OD
//启动子线程 h_?D%b~5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h\C
for(int i=0;i<nStartPos.length;i++) |=l;UqB
{ -DX|[70
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y!i4P#4+q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e.\d7_T+
nStartPos,nEndPos,i); Hh$D:ZO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |g> K$m^
fileSplitterFetch.start(); fcr\XCG7U
} !K'kkn,h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :b^tu8E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (BMFGyE3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Cf<i"
nEndPos = " + nFileLength); ~c! XQJ
// fileSplitterFetch[nPos.length-1].start(); =B*,S#r
J.?6a:#bU/
M,e_=aq
//等待子线程结束 1P3^il7
//int count = 0; W: cOzJ
//是否结束while循环 i4'?/UPc
boolean breakWhile = false; .2!'6;K
%l,p />r
O9=vz%
while(!bStop) #p*{p)]HiA
{ p[hA?dXn
write_nPos(); H1 n`A#6?
Utility.sleep(500); MCe=RR
breakWhile = true; "^zxq5u
Z)|*mJ
`DC)U1
for(int i=0;i<nStartPos.length;i++) ~(-B%Az
{ Pf]6'?kQ
if(!fileSplitterFetch.bDownOver) 3VB{Qj
{ ,8c`
breakWhile = false; 0#G&8*FMN
break; MJ8z"SKnV
} wR@fB
} +x-n,!(
if(breakWhile) 4B-v\3Ff
break; j?g{*M
;wp)E nF
i~n>dc YW
//count++; u <%,Ql
//if(count>4) d.% Vm&3
// siteStop(); hi*\5(uH
} ;?yd;GOt)
"[BuQ0(g
87>\wUJ
System.err.println("文件下载结束！"); K S,X$)9
} G7M:LcX
catch(Exception e){e.printStackTrace ();} Hl?\P6
} #8%Lc3n
'?v.O}
^B1Q";# B^
//获得文件长度 +*DXzVC
public long getFileSize() }a'8lwF%I
{ wP+wA}SN
int nFileLength = -1; BB|w-W=Kd
try{ d; oaG (e
URL url = new URL(siteInfoBean.getSSiteURL()); H^B/ '#mO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "DjD"?/b
httpConnection.setRequestProperty("User-Agent","NetFox"); }PK8[N
y_Bmd
y%cg
int responseCode=httpConnection.getResponseCode(); z./u;/:
if(responseCode>=400) Jf|J":S
{ *9`@
processErrorCode(responseCode); ]{0 2!
return -2; //-2 represent access is error Zc{at}{
} O6YYOmt3
BQ)zm
pI( OI>~3
String sHeader; L@ql)Lc);
s0E:hn:
{&4+W=0 n
for(int i=1;;i++) c9=;:E
{ 7-'!XD!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b9%hzD,MR
//Utility.log(in.readLine()); =eDVgOZ)
sHeader=httpConnection.getHeaderFieldKey(i); ql2>C.k3L
if(sHeader!=null) 2Af1-z^^K
{ 3EI$tP@4
if(sHeader.equals("Content-Length")) U9SByqa1
{ <FRYt-+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); egYJ.ZzF0
break; b=wc-nA
} J3oH^
} \.POb5]p0
else aHXd1\6m
break; p4fU/
} |/Ggsfmby
} (VI4kRj
catch(IOException e){e.printStackTrace ();} qYl%v
catch(Exception e){e.printStackTrace ();} f-k%P$"X&
dK#:io[Nz
lN<vu#
Utility.log(nFileLength); TXv3@/>ZlG
~N;kF.q&>&
!eMz;GZ
return nFileLength; q#xoM1
} "S,,BjL
>j4;{r+eQw
MQG(n+c
//保存下载信息（文件指针位置） -L NJ*?b
private void write_nPos() Ww{bh-nyq
{ 2!QJa=
try{ [GyW1-p33w
output = new DataOutputStream(new FileOutputStream(tmpFile)); YiTiJ9jf
output.writeInt(nStartPos.length); ,_!pUal
for(int i=0;i<nStartPos.length;i++) ;*BG{rkr
{ Q=)$
// output.writeLong(nPos); ey_3ah3x
output.writeLong(fileSplitterFetch.nStartPos); ,ZHIXylZ
output.writeLong(fileSplitterFetch.nEndPos); QgqR93Ic
} $>hPB[[
output.close(); D. fPHq
} "iMuA
catch(IOException e){e.printStackTrace ();} [o<Rgq4
catch(Exception e){e.printStackTrace ();} Kyq/'9`
} .D(H@3qA@
t3}>5cAxy
NoB)tAvw
//读取保存的下载信息（文件指针位置） bE74Ui
private void read_nPos() p`fUpARA!
{ g=0`^APql
try{ AU -,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j2#RO>`,I
int nCount = input.readInt(); V`fp%7W
nStartPos = new long[nCount]; }xk85*V
nEndPos = new long[nCount]; _/;vsQB
for(int i=0;i<nStartPos.length;i++) ve49m%NQ
{ DI{VJ&n66
nStartPos = input.readLong(); i+ ]3J/J
nEndPos = input.readLong(); UMILAoR
} bBk_2lg=4)
input.close(); F{WV}o=MY
} <wfPbzs-V
catch(IOException e){e.printStackTrace ();} }^+E S^~
catch(Exception e){e.printStackTrace ();} <~@}r\
} LUc!a4i"fO
{0RwjPYp
/H/@7>
private void processErrorCode(int nErrorCode) -GJ~xcf0
{ ~2PD%+e7]
System.err.println("Error Code : " + nErrorCode); 0/5 a3-3{
} wj!YYBH
A=JPmsj.
lD)ZMaaS3
//停止文件下载 `d2 r5*<
public void siteStop() /'' |bIPa
{ "4NcszEN
bStop = true; " R!,5HQF;
for(int i=0;i<nStartPos.length;i++) Q"7vzri
fileSplitterFetch.splitterStop(); Y&!-VW
$9YAq/#Q
.)59*'0
} ,P ~jO
} O_OgTa
//负责部分文件的抓取 Q=9Ce@[
**FileSplitterFetch.java @`xR1pXQ
*/ 6|:K1bI)
package NetFox; `yJ3"{uO
iY?J3nxD-:
@( p9}
import java.io.*; K~Nx;{{d
import java.net.*; 6l]jmj)/
C$WUg<kcK'
r&+8\/{
public class FileSplitterFetch extends Thread { +i^@QNOa
uE] HU
2>TOCBB"
String sURL; //File URL znnnqR0us
long nStartPos; //File Snippet Start Position |`eHUtjH
long nEndPos; //File Snippet End Position o]/*YaB2>
int nThreadID; //Thread's ID IJ\4S
boolean bDownOver = false; //Downing is over ^x2zMB\t
boolean bStop = false; //Stop identical "QSmxr
FileAccessI fileAccessI = null; //File Access interface /M!b3bmA
m&vuBb3
'^B[Krs'Z`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Cq8.^=}_
{ O{^8dwg
this.sURL = sURL; D8X~qt/
this.nStartPos = nStart; JOwm|%>3a
this.nEndPos = nEnd; D[/h7Ha
nThreadID = id; M5 \flE2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SG\6qE~
} .ni<'
!aQb Kp
AS4mJ UU9
public void run() Lmsc~~
{ fVf @Ngvu
while(nStartPos < nEndPos && !bStop) |2ImitN0
{ tVQq,_9C
#1fL2nlP*E
IVSOSl|
try{ .fFXH
URL url = new URL(sURL); 4j|IG/m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IC"Z.'Ph
httpConnection.setRequestProperty("User-Agent","NetFox"); ^+p7\D/E(
String sProperty = "bytes="+nStartPos+"-"; Mh"X9-Ot
httpConnection.setRequestProperty("RANGE",sProperty); 6mV-+CnYC
Utility.log(sProperty); /U26IbJ
6|uv+$
*T6*Nxs0k
InputStream input = httpConnection.getInputStream(); +~(SeTY
//logResponseHead(httpConnection); ~aPe?{yIUa
0:I[;Qt
PH.g+u=v
byte[] b = new byte[1024]; H^ 'As;R
int nRead; or,:5Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~Y/:]&wF
{ OEw#;l4 C
nStartPos += fileAccessI.write(b,0,nRead); |PtfG2Ty?
//if(nThreadID == 1) %lq[,6?>5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [s4|+
} tn{YIp
m^%@bu,
bog3=Ig-
Utility.log("Thread " + nThreadID + " is over!"); }#r awVe=
bDownOver = true; {x{~%)-
//nPos = fileAccessI.write (b,0,nRead); 7F2 WmMS
} Gsn$r(m{K
catch(Exception e){e.printStackTrace ();} 3D;?X@
} t)|~8xpP
} ]f{3_M[
-w"$[XP
4mjlat(d
//打印回应的头信息 ]sTbEw.[
public void logResponseHead(HttpURLConnection con) s<>d&W 0=
{ sZx`u+
for(int i=1;;i++) 2cEvsvw>
{ k?Kt*T
String header=con.getHeaderFieldKey(i); 7Q^p|;~a
if(header!=null) D%}rQ,*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t!-\:8n
Utility.log(header+" : "+con.getHeaderField(header)); {oSdVRI
else Nj;5iy
break; nuH=pIq6x
} /:tzSKq}
} 2##;[
*8r^!(Kj
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public void splitterStop() 577#A,O
{ Yt[LIn-v:
bStop = true; b)eoFc)lc
} 1etT."
%oB0@&!mS
ZIN1y;dJ
} [QFAkEJ--o
WeJ=]7T'L
IwXWtVL
/* ,wf:Fr
**FileAccess.java G2<$to~{
*//文件访问(定位，写) 5S<Rz)1r
package NetFox; #_eXybUV
import java.io.*; E.%V0}
b(oe^jeGz
wBDHhXi0
public class FileAccessI implements Serializable{ 0!-'4+"
:i4AkBNK
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0K'{w]Q
RandomAccessFile oSavedFile; 2?Y8hm
long nPos; qV9}N-sS
$PG(>1e
\ZM5J
public FileAccessI() throws IOException /qKA1-R}4
{ eC"k-a8j+
this("",0); |8pSMgN
} denxcDFu/~
{#st>%i
NN#k^[i1
public FileAccessI(String sName,long nPos) throws IOException Llkh kq_
{ IQ$!y,VJ
oSavedFile = new RandomAccessFile(sName,"rw"); SwsJ<Dq^z
this.nPos = nPos; eR4ib-nS
oSavedFile.seek(nPos); OK)>QGl
} wz1nV}
ul3~!9F5F
Tw djBMte
public synchronized int write(byte[] b,int nStart,int nLen) 8 :WN@
{ w$IUm_~waa
int n = -1; 4#{f8
try{ t{g@z3
oSavedFile.write(b,nStart,nLen); ^KdT,^6T
n = nLen; fF(AvMsO
} V:#rY5X
catch(IOException e) gg.]\#3g
{ z .Z
e.printStackTrace (); Mq#m;v$E
} @ R[K8
`*cqT
qdLzB
return n; /O<~n%< G
} 9 Jw,ls
>yr;Y4y7K
/lbj!\~
} K\wu9z8M
T;5VNRgpI
?%`Ph ?BZl
/* V@]SKbK}wN
**SiteInfoBean.java GMg!2CIU
*/ 3$xpZm60
package NetFox; ~r?tFE*+
Zr1"'+-
i6P}MtC1
public class SiteInfoBean { g4=C]\1
IqV"4
yKuZJXGVo
private String sSiteURL; //Site's URL CcW3o"=4
private String sFilePath; //Saved File's Path A +=#
private String sFileName; //Saved File's Name VH4wsEH]
private int nSplitter; //Count of Splited Downloading File i3mw.`7
ZJW8S
uB^"A ;0v
public SiteInfoBean() %19~9Tw
{//nSplitter的缺省值为5 pdm(7^
//default value of nSplitter is 5 ,}\LC;31,
this("","","",5); ^SsdM#E
} U#[T!E
[<5/s$,i
yZ7)|j
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Vpp$yM&?
{ .rG~\Ws
sSiteURL= sURL; w_o+;B|I
sFilePath = sPath; bl&9O
sFileName = sName; YhNrg?nS
this.nSplitter = nSpiltter; 45n.%*,
)5n0P Zi
:!l.ze{F
} }cI-]|)|2
vs$h&o>|
qLN\>Z,3;
public String getSSiteURL() R<gAxO%8
{ y9?*H?f,
return sSiteURL; Go1xyd:k
} R<_VWPlj
2q]ZI
c7{s'ifG
public void setSSiteURL(String value) ovOV&Zt
{ J~xm[^0
sSiteURL = value; `q\F C[W
} /k?l%AH
H{yBDxw
kP}l"CN4
public String getSFilePath() VRgckh m
{ n|?sNM<J3
return sFilePath; (SQGl!Lai0
} *Gv:N6
E.;Hm;
n:B){'S
public void setSFilePath(String value) jbq x7x
{ y`8U0TE3R
sFilePath = value; Ym"^Ds}
} I L7kpH+y
Du +_dr^4
QHja4/
public String getSFileName() WF*j^ %5
{ xjF>AAM_Px
return sFileName; ~:k r;n2
} )7!,_r
TghT{h@
<$hv{a
public void setSFileName(String value) 4YI6&
{ c%O97J.5b
sFileName = value; Ek_&E7
} )MSCyPp5
A$7K5
@aN~97 H\
public int getNSplitter() k"%JyO8Y
{ Nt]nwae>A
return nSplitter; hrD2-S
} Xjxa 2D
o3\^9-jmp
f3n^Sw&Q(Q
public void setNSplitter(int nCount) suIYfjh
{ o<p4r}*AVJ
nSplitter = nCount; %-fS:~$
} p %.Adxx
} p<h(
bC"h7$3
Ac{TqiIv
/* ^b~ZOg[p
**Utility.java _t;^\"\
*/ -IVWkA)7
package NetFox; OGLA1}k4
G5OGyQp
qhG2j;
public class Utility { mJd8?d
"[k>pzl6
yMM2us#*+q
public Utility() G;#xcld
{ DF-PBVfpu
Vv5T(~
55TFBDc
} pO fw *lD
Het>G{
//线程睡眠 6C<GYzzo
public static void sleep(int nSecond) %XBTN
{ /qwY/^
try{ Z8/.I
Thread.sleep(nSecond); ^V9|uHOJoq
} Gg GjBt
catch(Exception e) -R1;(n)
{ gaNe\
e.printStackTrace (); _,v?rFLE
} B 5qy4MFWs
} e2G;_:
pRxVsOb
//日志 ~*\ *8U@7
public static void log(String sMsg) %jf|efxo
{ 7rbw_m`12-
System.err.println(sMsg); 'byTM?Sp{
} (RrC<5"
o(> #}[N}
-OmpUv-O"
public static void log(int sMsg) Ktt(l-e+
{ )+Z.J]$O-
System.err.println(sMsg); b&QI#w
} C|g1:#0
} FYu30
wxBZ+UP_
E@)'Z6r1
/* vaHtWz!P
**TestMethod.java ;gu4~LQw
*/ |9.J?YP8 (
package NetFox; H/Ql
Y%y
B<Cg_C
public class TestMethod { 2'OY,Ooe
@qW$un:
Unq~lt%2
public TestMethod() nFI<Te^)
{ ///xx/weblogic60b2_win.exe t5i58@{~
try{ :kE*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -vc$I=b;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =\oW{?
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9C Ki$L
fileFetch.start(); ,JbP~2M~%
} m:~y:.
catch(Exception e){e.printStackTrace ();} .X)Wb{7
Ay^P#\VZ
MT)q?NcG
} ,Csjb1
P*%P"g
<tsexsw
public static void main(String[] args) i|,}y`C#
{ H"Hl~~U
new TestMethod(); l=Jw6F+5
} 3fX_XH1Q
} N7}3?wS
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