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)); =fsaJ@q,R
} d:pp,N~2o
for(int i=0;i<nEndPos.length-1;i++) h.?[1hT4R
{ "L8V!M_e
nEndPos = nStartPos[i+1]; )D[ypuM&
} BB%(!O4Dl
nEndPos[nEndPos.length-1] = nFileLength; LpmspIPvf
} 9d{W/t?NH
} =k$d8g ez
Q%eBm_r;
^1~/FU
//启动子线程 pM46I"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !r LHPg
for(int i=0;i<nStartPos.length;i++) Hzj*X}X#K
{ $AXz/fGV
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %x927I>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O]Kb~jkd
nStartPos,nEndPos,i); }TF<C!]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6U&Uyd)
fileSplitterFetch.start(); P);Xke
} )K?GAj]Pq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ! 4oIx`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5t<]|-i!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #>- rKv.A
nEndPos = " + nFileLength); ^m+W
// fileSplitterFetch[nPos.length-1].start(); ,gOQIS56
;etQ
ttsB'|ps
//等待子线程结束 8uT6QCf
//int count = 0; .|aSGvE
//是否结束while循环 aDOH3Ri0K!
boolean breakWhile = false; 1|nB\xgu
E{fnh50^Q.
)I>rC%2P
while(!bStop) )/U1; O
{ IL\mFjZ'
write_nPos(); i&HV8&KygN
Utility.sleep(500); d#d~t[=
breakWhile = true; `UI)H*GA8
}fCM_w
p!a%*LfND
for(int i=0;i<nStartPos.length;i++) 19rUvgC{M
{ ..T(9]h
if(!fileSplitterFetch.bDownOver) z<fEJN
{ _@p|A
breakWhile = false; *Qf}4a0
break; dXDD/8E
} Yq Fzbm{\
} b5|p#&YK~
if(breakWhile) Q|1bF!#(1
break; :I$2[K
AFFLnLA<L
\l2 s^7G_
//count++; {DK:"ep
//if(count>4) 3?XLHMxW
// siteStop(); &\H5*A.HkA
} =z/F=1^<
D1n2Z:9
2|=_kN8;
System.err.println("文件下载结束！"); kwL)&@
} Ih7Eq/iu
catch(Exception e){e.printStackTrace ();} (lnQ!4LK
} v wyDY%B"n
qLP+@wbJ
?>y-5B[K/(
//获得文件长度 @ 7?_Yw
public long getFileSize() m?j!0>
{ wuk7mIJ
int nFileLength = -1; U.aa iX7
try{ -^b^6=#
URL url = new URL(siteInfoBean.getSSiteURL()); JqUVGEg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ie(7m|.
httpConnection.setRequestProperty("User-Agent","NetFox"); tTt3D]h(
kOCxIJ!Xp=
wuzz%9;@B
int responseCode=httpConnection.getResponseCode(); =5ih,>>g
if(responseCode>=400) MuobMD}jqe
{ W/>?1+r.Z
processErrorCode(responseCode); gQuw|u
return -2; //-2 represent access is error +29\'w,
} 32iI :u
Hl;p>>n
ymZ/(:3_
String sHeader; hU 7fZl%yl
#Qr4Ke$g[l
Gme$FWa
for(int i=1;;i++) H/k W :k
{ @vYmkF`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @q/1m~t
//Utility.log(in.readLine()); ak) -OL1
sHeader=httpConnection.getHeaderFieldKey(i); mi<D bnou
if(sHeader!=null) )$B+3f
{ ,)$KS*f"*z
if(sHeader.equals("Content-Length")) Yp]G)}'R
{ (AG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =&pN8PEn\
break; o0G`Xn
} 8-a6Q|
} A+*oT(`
else A{I a21T7
break; n2mw@Ay!
} aNC,ccm
} -1
catch(IOException e){e.printStackTrace ();} g>xUS_d>
catch(Exception e){e.printStackTrace ();} %hbLT{w
kc'0NE4oq
/iy*3P,`
Utility.log(nFileLength); 1?RCJ]e5
AdEbyL
OgN1{vRFx
return nFileLength; iM|"H..
} 4l}M i
$U1kP?pR
cNo4UZvr
//保存下载信息（文件指针位置） \678Nx
private void write_nPos() 9G&l qfX:
{ SxZ^ "\H
try{ bsi q9$F
output = new DataOutputStream(new FileOutputStream(tmpFile)); tnF9Vj[#%_
output.writeInt(nStartPos.length); '}+X,Usm
for(int i=0;i<nStartPos.length;i++) y8hg8J|
{ [du>ff
// output.writeLong(nPos); j]B$(pt
output.writeLong(fileSplitterFetch.nStartPos); {QS@Ugf
output.writeLong(fileSplitterFetch.nEndPos); mu6xL QdA
} 3.<6;?
output.close(); \8*,&ak%
} ^s@*ISY
catch(IOException e){e.printStackTrace ();} an=+6lIl
catch(Exception e){e.printStackTrace ();} }C{}oLz
} ;WS7.
BY4 R@)
[B~zoB(
//读取保存的下载信息（文件指针位置） ]PzTl {]
private void read_nPos() o;VkoYV
{ KBr5bcm4u
try{ < k+fKl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T]nR=uK6LL
int nCount = input.readInt(); _.OMjUBZT
nStartPos = new long[nCount]; ^?6 W<
nEndPos = new long[nCount]; 1>@]@ST[:
for(int i=0;i<nStartPos.length;i++) YZBzv2'\x
{ V^ fGRA
nStartPos = input.readLong(); kg?T$}O
nEndPos = input.readLong(); cPx~|,)l
} 7/&C;"
input.close(); 6t_ 3%{
} B15O,sL&W
catch(IOException e){e.printStackTrace ();} r%TLv
catch(Exception e){e.printStackTrace ();} P )t]bS
} T+K` ^xv_L
T3G/v)ufd
#0?"J)
private void processErrorCode(int nErrorCode) 1=/doo{^
{ [>$\s=` h
System.err.println("Error Code : " + nErrorCode); qD(fYOX{C
} #}/cM2m
BP[CR1Gs
G>=9gSLM
//停止文件下载 _OJ0 < {E
public void siteStop() 3yHb!}F
{ _'!N q
bStop = true; ko=aa5c
for(int i=0;i<nStartPos.length;i++) 6z9R1&~%
fileSplitterFetch.splitterStop(); BaWQ<T8p8
0<]$v"`I
< v|%K.yd
} aPD?Bh>JU
} VM-qVd-
//负责部分文件的抓取 lL:KaQ0E
**FileSplitterFetch.java L _vblUDq
*/ 7oZ@<QP'
package NetFox; saGRP}7?
C<[d
Iz6ss(UJ
import java.io.*; 22)0zY%\
import java.net.*; iEiu%T>
zyaW3th
&u+yM D
public class FileSplitterFetch extends Thread { =dgo!k
|. J,8~x
8g<Q5(
String sURL; //File URL %/UV_@x&
long nStartPos; //File Snippet Start Position +<pVf%u5
long nEndPos; //File Snippet End Position M0cd-Dn
int nThreadID; //Thread's ID +<S9E'gT3V
boolean bDownOver = false; //Downing is over u|(Ux~O
boolean bStop = false; //Stop identical 6N9 c<JC
FileAccessI fileAccessI = null; //File Access interface qq OxTG]
8h*t55
tlDYk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1S+;ZMk
{ nAIH`L"X
this.sURL = sURL; _,DO~L
this.nStartPos = nStart; ?TIV2m^?
this.nEndPos = nEnd; WHp97S'd
nThreadID = id; ki\B!<uv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mfZ)^X
} t";{1.
"Owct(9
FXS^^p P
public void run() $[[?;g
{ *3;UAfHv
while(nStartPos < nEndPos && !bStop) 8jRs=I
{ ]53O}sH>
}x]&L/
a*D,*C5}
try{ cI2Fpf`2Wj
URL url = new URL(sURL); q^5yk=2fq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %Nj #0YF]
httpConnection.setRequestProperty("User-Agent","NetFox"); +fM&su=wl
String sProperty = "bytes="+nStartPos+"-"; 0|ZVA+
httpConnection.setRequestProperty("RANGE",sProperty); W$r^
Utility.log(sProperty); VKy5=2&
XlVc\?
bMsECA&
InputStream input = httpConnection.getInputStream(); &M[MEO`t8
//logResponseHead(httpConnection); F$i$a b
Zb."*zL
fmFzW*,E
byte[] b = new byte[1024]; k=?^){[We
int nRead; (%bE~Q2P*<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b4CF`BG
{ q]TqI' o
nStartPos += fileAccessI.write(b,0,nRead); FqwIJ|ct
//if(nThreadID == 1) fYB*6Xb,w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .Rvf/-e
} &iNS?1a%f=
}%$OU =T
Q/py qe G
Utility.log("Thread " + nThreadID + " is over!"); DVh)w}v
bDownOver = true; ox[ .)v
//nPos = fileAccessI.write (b,0,nRead); /g@^H/DO
} +"8}R~`!
catch(Exception e){e.printStackTrace ();} 3CM^j<9
} 3rNc1\a;
} i6Qb[\;
-w]/7cH
hsz^rZ
//打印回应的头信息 e[{mVhg4E
public void logResponseHead(HttpURLConnection con) p x#suy
{ r+S;B[Vd
for(int i=1;;i++) 4&{!M _
{ 1HbFtU`y~
String header=con.getHeaderFieldKey(i); O9^T3~x[V
if(header!=null) b9uBdo@o
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^I`a;
Utility.log(header+" : "+con.getHeaderField(header)); ]g,lRG
else >b48>@~bY
break; jO8X:j09A
} q@l(Qol
} DnFjEP^
k!3 cq)
{<K=*rrZ
public void splitterStop() fx)KNm8Lx
{ xS8,W
bStop = true; oa`#RC8N
} dZ]Rqr _!
g jxS
,lm=M5b
} $UvPo0{
W~ruN4q.
:(,mL2[
/* vHcqEV|P/n
**FileAccess.java 3^wC<ZXcD
*//文件访问(定位，写) 0<.RA%dj
package NetFox; `}fw1X5L
import java.io.*; @iLIU}+
% frfSGf.#
|PP.<ce\-
public class FileAccessI implements Serializable{ =&vFVIhWcf
{(tHk_q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _<*Hv*Zm
RandomAccessFile oSavedFile; O{]9hm(tN
long nPos; 57Z-
I7(?;MpI
P^)q=A8Z#
public FileAccessI() throws IOException :iPym}CE
{ Y; ).+si
this("",0); vmX"+sHz$]
} Eu,`7iQ?(
_O]xey^r
_}gtcyx
public FileAccessI(String sName,long nPos) throws IOException Vf $Dnu@}z
{ A''pS
oSavedFile = new RandomAccessFile(sName,"rw"); PaWr[ye
this.nPos = nPos; rwf^,r"r
oSavedFile.seek(nPos); )rtomp:X
} GTl xq%?b
s?C&s|'.
j !H^-d}q
public synchronized int write(byte[] b,int nStart,int nLen) n<7q`tM#
{ Jxl6a:
int n = -1; A1i!F?X
try{ _NZ@4+aW
oSavedFile.write(b,nStart,nLen); #,NvO!j<4
n = nLen; O7G"sT1Dv
} }} ZY
catch(IOException e) )>a B
{ ('[TLHP
e.printStackTrace (); fAZiC+
} V8=Y@T,
Z%Z9oJ:
B7\k< Nit0
return n; *%Qn{x
} {%w!@-
,n!vsIN
2/,0iwj-
} OS7RQw1
B< ;==|
a#(U2OP
/* c;!g
**SiteInfoBean.java E1q%gi4Q%
*/ (}H ,ng'4
package NetFox; 4KIWb~0Y
IlZu~B9c
N_'+B+U?
public class SiteInfoBean { @6.]!U4w
]S/G\z
{Bs+G/?o/
private String sSiteURL; //Site's URL $+VgDe5{S
private String sFilePath; //Saved File's Path r5Wkc$
private String sFileName; //Saved File's Name xz="|HD);
private int nSplitter; //Count of Splited Downloading File kU>#1He
"1\(ZKG8^Q
0rGj|@+;
public SiteInfoBean() XZ;*>(
{//nSplitter的缺省值为5 vN'VDvVM
//default value of nSplitter is 5 ,%.:g65%
this("","","",5); ?F!W#
} &~42T}GTWG
S54gqc1S]
9k*^\@\\x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yr (g~MQ
{ z`;&bg\8
sSiteURL= sURL; ]kzv8#
sFilePath = sPath; Am]2@ESUP
sFileName = sName; (xjqB{U
this.nSplitter = nSpiltter; #IbS
J,.j_ii`!
HIQ]"Hl
} \=$EmHF
t@l(xnsV
(X0`1s
public String getSSiteURL() Sa(yjF1
{ rDK;6H:u{
return sSiteURL; #_?426Wfs
} ?r^ hmu"a
.G7]&5s
5@GD} oAn6
public void setSSiteURL(String value) 8Pl+yiB/o`
{ 'Wo?%n
sSiteURL = value; hP,b-R9\
} /8 e2dw: \
2V#c[%vI
/5L'9e
public String getSFilePath() V[BY/<z)A
{ 6M O|s1zk
return sFilePath; YlZYS'_
} u=_bM2;~Z
,6S_&<{
'7S!6kd?
public void setSFilePath(String value) )nf=eU4|
{ ~%cSckE
sFilePath = value; uW\@x4
} EqNz L*E
?.4yg(
z'vdC
public String getSFileName() xI.Orpw
{ Uxj<x`<1x
return sFileName; 1kz9>;Ud6
} A{DIp+
.(P@Bl]XJ
!q7;{/QM6
public void setSFileName(String value) wHBHkz
{ XudH
sFileName = value; p[af[!
} }(f.uN_v
n6}E4Eno
O&rD4#
public int getNSplitter() 'NG^HLD/
{ [t"_}t=w
return nSplitter; 34+)-\xt:
} P0`>{!r6@
=hOj8;2
$,z[XM&9)
public void setNSplitter(int nCount) I;Z`!u:+
{ t9$AvE#a!=
nSplitter = nCount; c|R3,<Q]
} F=*BvI"+
} pZ@W6}
A^= Hu,"e
8IT_mjj
/* NejsI un%
**Utility.java QJ(e*/
*/ 6/V{>MTZg
package NetFox; $&n240(
n{qw]/
@LkW_
public class Utility { ]X"i~$T1S
J4'!
)z4kP09
public Utility() WW8L~4Zy
{ ?O.6r"
go%X%Os]
F|n$0vQ*
} eqUn8<<s
*`pec3"
//线程睡眠 L2/<+Zw
public static void sleep(int nSecond) ]Xkc0E1
{ Ie`SWg*WL
try{ 6!Tf'#TV~!
Thread.sleep(nSecond); i>kNz(*
} Cn./Naq
catch(Exception e) 9>$%F;JP44
{ 3/SqXu
e.printStackTrace (); 8 *(W |J
} ETH#IM8J
} UNZVu~WnF
Velbq
//日志 I!0$% ]F
public static void log(String sMsg) omUl2C
{ UgP=k){
System.err.println(sMsg); vsr~[d=
} Dk{nOvZu<
XGrxzO|{
C>K"ZJ
public static void log(int sMsg) B=RKi\K6a
{ 0\ytBxL
System.err.println(sMsg); iNrmhiql
} ;uo|4?E:\(
} QX~72X=(
7QL) }b.H
>,Swk3
/* r@V(w`
**TestMethod.java +iDz+3v(
*/ eEds-&_
package NetFox; 'w$we6f
bA9dbe
%^@0tT
public class TestMethod { By"ul:.D
gdn,nL`dP
?B31t9
public TestMethod() 9lwo/(s
{ ///xx/weblogic60b2_win.exe }j<_JI
try{ 6 VJj(9%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [zt&8g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9Qm{\
SiteFileFetch fileFetch = new SiteFileFetch(bean); NZ? =pfK\s
fileFetch.start(); Vh-h{
} 5TW<1'u
catch(Exception e){e.printStackTrace ();} y]z#??
z&G3&?Z
\Hx#p`B%
} ?=o]Wx0(9
si4=C
vP;tgW9Qk
public static void main(String[] args) +?eAaC7s
{ "+"dALX{3K
new TestMethod(); /u1zRw
} )W7H{#
} R}mWHB_h"
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