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)); ,c"_X8Fkx$
} QytqO{B^
for(int i=0;i<nEndPos.length-1;i++) ~k+"!'1
{ P0U=lj/b
nEndPos = nStartPos[i+1]; x8%Q TTY
} 7uJy<O
nEndPos[nEndPos.length-1] = nFileLength; kXS_:f;M
} lZCvH1&"
} yA*~O$~Y
*v3/8enf
aNb=gjLpt
//启动子线程 kRNr`yfN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1\q(xka{
for(int i=0;i<nStartPos.length;i++) Sr~zN:wn
{ }Q_IqI[7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yrO'15TB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FT73P0!8.
nStartPos,nEndPos,i); ?KpHvf'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !o~% F5|t
fileSplitterFetch.start(); V1Dwh@iS
} (:E_m|00;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9F)v=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x P{L%.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XG ]yfux`
nEndPos = " + nFileLength); Py\xN
// fileSplitterFetch[nPos.length-1].start(); $K^"a
Z@&_ T3M
+B^/ =3P
//等待子线程结束 aB<~T[H%h
//int count = 0; B, nCx=\S
//是否结束while循环 x3>K{
boolean breakWhile = false; CF9a~^+%
dluNA(Xc-
T8>:@EL-k
while(!bStop) Fh& `v0
{ `g6XVa*%#
write_nPos(); w[\*\'Vm0
Utility.sleep(500); wl^bvHG
breakWhile = true; t ),~w,7(J
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t3u"2B7oG
for(int i=0;i<nStartPos.length;i++) bO1J#bcZ
{ 'p-jMD}O
if(!fileSplitterFetch.bDownOver) dgpo4'c}
{ I<|)uK7
breakWhile = false; (:2:_FL
break; VaQ>g*(I
} mbv\Gn#>
} ,@%1q)S?A
if(breakWhile) {YWj`K
break; S%uH*&`
xc Wr hg
'#$%f
//count++; !y$Hr[v
//if(count>4) {%. _cR2
// siteStop(); q,VJpqQ
} 3 1KMn
Tn2Z{.q$
@gENv~m<OI
System.err.println("文件下载结束！"); )u]J`.OA
} 4;Z`u.1
catch(Exception e){e.printStackTrace ();} '|&}rLr:+
} w{)*'8oCB
UBqA[9
hLGUkG?6G
//获得文件长度 ]B=B@UO@.
public long getFileSize() <(`dU&&%"}
{ Fwyv>U
int nFileLength = -1; ^Tc&?\3
try{ KCJ zE>
URL url = new URL(siteInfoBean.getSSiteURL()); 1qbd6D|t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (7`goi7M
httpConnection.setRequestProperty("User-Agent","NetFox"); GjE/!6b
|M#b`g$JO,
P482D)
int responseCode=httpConnection.getResponseCode(); iN+Dmq5
if(responseCode>=400) j(F%uUpN
{ 6=A2Y:8
processErrorCode(responseCode); }M?GqA=
return -2; //-2 represent access is error sY7:Lzs.,
} 2,puu2F
Z!G_" 3
&}32X-~y
String sHeader; ^i_mGeu
?;>s<
c.6u)"@$
for(int i=1;;i++) rEfk5R
{ |TF,Aj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \D?6_ ,O
//Utility.log(in.readLine()); hD{+V!{
sHeader=httpConnection.getHeaderFieldKey(i); B<DvH"+$
if(sHeader!=null) l@Ma{*s6=5
{ (ZQ{%-i?qR
if(sHeader.equals("Content-Length")) ]8ua>1XS
{ E:xpma1Qf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nf+8OH7
break; }cgEC-
} )52:@=h*l
} 15VOQE5Fl`
else ps"crV-W
break; uljd)kLy4O
} Gv>,Ad ka
} dr^pzM!N
catch(IOException e){e.printStackTrace ();} dm,7OQ
catch(Exception e){e.printStackTrace ();} ,$Qa]UN5Q
"p.MJxH
.x$+R%5U
Utility.log(nFileLength); ]kbmbO?M
rmUTl
&|iFhf[o
return nFileLength; pA='(G
} K8Gc5#OF
|@]J*Kh
=+~e44!~D
//保存下载信息（文件指针位置） Un^QNd>
private void write_nPos() !jMa%;/
{ [0yKd?e
try{ [|d:QFx
output = new DataOutputStream(new FileOutputStream(tmpFile)); oc?,8I[P5
output.writeInt(nStartPos.length); iOPv %[
for(int i=0;i<nStartPos.length;i++) D#x D-c
{ + htTrHjt
// output.writeLong(nPos); %*e6@Hm
output.writeLong(fileSplitterFetch.nStartPos); CY)/1 # J
output.writeLong(fileSplitterFetch.nEndPos); !~04^(
} p&B98c
output.close(); &zlwV"W
} :g2?)Er-
catch(IOException e){e.printStackTrace ();} uT8/xNB!
catch(Exception e){e.printStackTrace ();} $Eg|Qc-1
} -LzHCO/7(
rK)So#'
!e&ZhtTuC
//读取保存的下载信息（文件指针位置） `Q1S8i$
private void read_nPos() r|:|\"Yk
{ A`Z!=og=
try{ j;<Yje&Wz
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -2o4v#d
int nCount = input.readInt(); VxLq,$B76
nStartPos = new long[nCount]; <oI{:KH
nEndPos = new long[nCount]; w3PE.A"Q
for(int i=0;i<nStartPos.length;i++) djS?$WBpU
{ b(_PCVC
nStartPos = input.readLong(); -_ .f&l8
nEndPos = input.readLong(); bRJYw6oA<
} GbwcbfH
input.close(); SOE#@{IXBa
} a)MjX<y
catch(IOException e){e.printStackTrace ();} dI5Z*"`R9
catch(Exception e){e.printStackTrace ();} lu`\6
} ^HLi1w|
Z6!MX_ep
UA!h[+Z
private void processErrorCode(int nErrorCode) }C/u>89%q
{ C#emmg!a\
System.err.println("Error Code : " + nErrorCode); pM@|P,w {
} |]RV[S3v
/gL(40
v{i'o4
//停止文件下载 q5 I2dNE
public void siteStop() x|_%R v
{ Zd1+ZH
bStop = true; /[VafR!
for(int i=0;i<nStartPos.length;i++) (BVLlOo?J
fileSplitterFetch.splitterStop(); M-K<w(,X
'C1=(PE%`
3Ku!;uo!u
} ; @ h{-@
} AT<gV/1l
//负责部分文件的抓取 00Tm0rY
**FileSplitterFetch.java V=VL@=
*/ +&jWM-T"-
package NetFox; u ?7(A%
H;k;%Zg;
;/N[tO?Q
import java.io.*; >>rW-&
import java.net.*; ?t'ZX~k
4HVZ;,q
!.zUY6
public class FileSplitterFetch extends Thread { ?O8NyCeb7
Nb>|9nu O
%:h)8e-;
String sURL; //File URL >T%Jlj3ZG
long nStartPos; //File Snippet Start Position lJ3/^Htn
long nEndPos; //File Snippet End Position _J6|ju\
int nThreadID; //Thread's ID $)mq
boolean bDownOver = false; //Downing is over p/:)Z_
boolean bStop = false; //Stop identical _b<Fz`V
FileAccessI fileAccessI = null; //File Access interface ;9q3FuR
YPDc /
)-Zpr1kD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6dV@.(][a
{ xrA(#\}f$
this.sURL = sURL; GxLoNVr
this.nStartPos = nStart; j?jEWreq]~
this.nEndPos = nEnd; ?g}n$%*5y!
nThreadID = id; 4};!nYey!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bS3qX{5
} KunK.m
"6~pTHT
e!l!T@ pf
public void run() aa_&WHXkt
{ RsIEY5Q
while(nStartPos < nEndPos && !bStop) Q nDymVF
{ q =b.!AZy
!aeL*`;
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try{ V,<,;d fR
URL url = new URL(sURL); K8pfk*NZ_@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rwtSn?0z"
httpConnection.setRequestProperty("User-Agent","NetFox"); QBR9BR
String sProperty = "bytes="+nStartPos+"-"; k)'hNk"x
httpConnection.setRequestProperty("RANGE",sProperty); :M`|*~V~$
Utility.log(sProperty); [zm&}$nnN
%/oOM\}++
?|%^'(U}
InputStream input = httpConnection.getInputStream(); T$06DS
//logResponseHead(httpConnection); 8d-; ;V
25l6@7q.
1T%Y:0
byte[] b = new byte[1024]; G#HbiVH9
int nRead; 0(Vbji
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z9i,#/
{ {v+i!a'+
nStartPos += fileAccessI.write(b,0,nRead); &s"&rFFO[
//if(nThreadID == 1) wHBkaPO!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a{L`C"rJ
} K-)*S\<}
Y`LZ/Tgk
~{n_rKYV
Utility.log("Thread " + nThreadID + " is over!"); UQ$dO2^
bDownOver = true; m1gJ"k6 `j
//nPos = fileAccessI.write (b,0,nRead); ]"dZE2!
} j23OgbI
catch(Exception e){e.printStackTrace ();} n8w|8[uV^
} ;J2U5Y NO
} Gnl6>/L,
$9y]>R
}kT;UdIu;
//打印回应的头信息 %{yr#F=t#]
public void logResponseHead(HttpURLConnection con) nqBZp N^
{ bFVz ;
for(int i=1;;i++) 9|v
{ vROl}s;
String header=con.getHeaderFieldKey(i); *<x]gV
if(header!=null) .Ap[C? mV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >RHK6c
Utility.log(header+" : "+con.getHeaderField(header)); q+~z# jFX
else go]d+lhFB
break; ]RPv@z:V
} J,;;`sf
} Ufq"_^4
%pc0a^iB
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public void splitterStop() Ki^m&P
{ R=i$*6}a
bStop = true; L -b~#
} vn .wM
RL~\/#
`.MM|6
} q .tVNKy%
_( w4\]
KAgiY4
/* ZZ!d:1'7
**FileAccess.java `vDg~o
*//文件访问(定位，写) 9=rYzA?)+
package NetFox; \&R}JK
import java.io.*; ,<R/x[
IqfR`iAix
b=F"
public class FileAccessI implements Serializable{ &m'O :ZS2
PX?tD:,[-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 csRba;Z[
RandomAccessFile oSavedFile; PaMi5Pq
long nPos; YxS*im[%]
(Uv{%q.n6
0w< iz;30
public FileAccessI() throws IOException tOnaD]J
{ :lgIu .
this("",0); \Y>^L{
} I4m)5G?O2
2}[rc%tV:?
d;D^<-[i
public FileAccessI(String sName,long nPos) throws IOException q1r\60M
{ tK g%5;v
oSavedFile = new RandomAccessFile(sName,"rw"); xW/JItF
this.nPos = nPos; 5c{=/}Y
oSavedFile.seek(nPos); XwX1i!'54
} 7; TS
66:|)
r\@"({q}_-
public synchronized int write(byte[] b,int nStart,int nLen) ;NRm ,
{ Jfo|/JQ
int n = -1; )lB-D;3[_
try{ zLOmtZ(['
oSavedFile.write(b,nStart,nLen); g\rujxHlH
n = nLen; PA`b~Ct
} jd]MC*%
catch(IOException e) "N4c>2Q
{ xqP0Z),Ow
e.printStackTrace (); m$QFtrvy
} -W!g>^.
" 8;D^
/Klwh1E
return n; js;IUSj.
} LFen!FnM
8'^eH1d'
~+l%}4RZ
} oWs&W
vFl|
_32ltnBX
/* !Z%QD\knY
**SiteInfoBean.java @m6pAo4P
*/ CtjjN=59
package NetFox; oS_'@u.5
uKpl+>
86R}G/>>e
public class SiteInfoBean { -6+HA9zz@C
pNVao{::5
G<Lm}
private String sSiteURL; //Site's URL xs.[]>nQN
private String sFilePath; //Saved File's Path kwWO1=ikz@
private String sFileName; //Saved File's Name iW*0V3
private int nSplitter; //Count of Splited Downloading File FuEHO6nx
*aG0p&n}
@3VL _g:
public SiteInfoBean() =%2 E|/
{//nSplitter的缺省值为5 [jAhw>
//default value of nSplitter is 5 cv#H
this("","","",5); (O?z6g
} <6v7_
B-@f.NO/s
<@JU0Z"a=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #GWQ]r?
{ *D4H;P#
sSiteURL= sURL; >4h4t/G
sFilePath = sPath; P-+^YN,
sFileName = sName; fK4laDBTO
this.nSplitter = nSpiltter; 8 ehC^Cg
Xk7zXah
zoUW}O
} TuaT-Z~U{
zYls>fbp,
r9b`3yr=
public String getSSiteURL() K''b)v X4
{ !Y\hF|[z
return sSiteURL; HnOF_Twq
} /Zm@.%.
<a$cB+t
YRC`2)_'
public void setSSiteURL(String value) NA0hQGN}
{ 3P#1fI(c
sSiteURL = value; z,2m7C
} Dtr'X@U
5O*+5n
veK
public String getSFilePath() vP,WV9Q1u
{ *}mtVa_|
return sFilePath; _10#rucr
} @XmMD6{<
?.4.Ubc\
7[u&%
public void setSFilePath(String value) -P.) 0d(
{ sjaG%f&h
sFilePath = value; 5R o5Cg~
} yM\1n
8,B9y D
\OY2|
public String getSFileName() m m`:ci
{ xmVK{Q YT$
return sFileName; rNgE/=X
} 8|J%IE
}>tUkXlhJ<
-Tz9J4xU&
public void setSFileName(String value) -nHc52,
{ E"w7/k#3}C
sFileName = value; &JF^a
} d6M d~$R
cDAO5^
$"_D"/*
public int getNSplitter() Z ,T TI>P
{ pl7!O9bo
return nSplitter; x&;{4F Nw
} ?np`RA
cFH,fj
R0m}I5Frs
public void setNSplitter(int nCount) =(hEr=f>7
{ X7n~Ws&s@
nSplitter = nCount; B*?v`6
} ?!A{n3\<
} JFZZ-t;*
e@I?ESZ5
Y$,]~Qzq
/* IHB{US1G
**Utility.java ?;i6eg17<
*/ RS$:]hxd>_
package NetFox; hVR=g!e#X
X59~)rH,
v"bOv"!al
public class Utility { yWX:`*GV
^M,Q<HL
g4-HUc zk
public Utility() Yoaz|7LS
{ "}ZD-O`!
85H8`YwPh
.e]!i(5I
} [!DLT6Qk
F%< 0pi
//线程睡眠 rV1JJ.I
public static void sleep(int nSecond) ) tsaDG-E
{ e`C'5`d]
try{ Bj\0RmVa1
Thread.sleep(nSecond); m >'o&Hj
} K_}vmB\2l
catch(Exception e) %=_Iq\lC
{ rb,&i1
e.printStackTrace (); *8MU,6
} b$M? _<G
} ]Oe#S"-Oo
B)Gm"bLCOZ
//日志 XmXHs4
public static void log(String sMsg) y]@_DL#J=
{ 9]d$G$Kv9
System.err.println(sMsg); Kk#8r+,
} BWQ (>Z"
*t*yozN
Eb#0-I
public static void log(int sMsg) !".@Wg$
{ c%v%U &
System.err.println(sMsg); U?@UIhtM|
} qwVpGNc45
} ;O.U-s
``zg |h
O5e9vQH
/* Gn&)*qCO
**TestMethod.java <0Q`:'\.>
*/ UT>\u
package NetFox; \1|T
&@{Ba~S
=f{r+'[;^
public class TestMethod { ~KrzJp=5F
J *^|ojX
]D<r5P%
public TestMethod() x{IOn;>R
{ ///xx/weblogic60b2_win.exe /G</ [N5
try{ whRc YnJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |\elM[G"g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .dl1sv U
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9jJ&QACn
fileFetch.start(); x?f3XEA_
} R$cg\DD
catch(Exception e){e.printStackTrace ();} {n|Ra[9_
^oPf>\),C
x'n J_0
} |J~;yO SD
$ V}s3
*I>1O*
public static void main(String[] args) 4Mnne'7
{ o6oZk0
new TestMethod(); :)%Vahu
} 1Te:&d
} X0p=jBye~>
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