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)); v!8=B21
} a8f#q]TyQ
for(int i=0;i<nEndPos.length-1;i++) |82q|@e
{ 7IkPi?&{
nEndPos = nStartPos[i+1]; HJ]xZ83pC
} =w!ik9
nEndPos[nEndPos.length-1] = nFileLength; ? Bpnnwx
} a(|6)w-
} @^<odmM
RkE)2q[5
!,$#i
//启动子线程 )A$"COM4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :YI5O/gsk?
for(int i=0;i<nStartPos.length;i++) :Ln)j%&
{ Tb$))O}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >UvP/rp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +Yc^w5 !(
nStartPos,nEndPos,i); "esuLQC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o{G*7V@H
fileSplitterFetch.start(); w6i2>nu_O
} T82 `-bZ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gS5REC4I/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dS ojq6M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Jt=->
nEndPos = " + nFileLength); -Cs( 3[
// fileSplitterFetch[nPos.length-1].start(); fAgeF$9@
Jy)=TJ!y
Y"H`+UV
//等待子线程结束 |%C2 cx
//int count = 0; t1Fqq4wRi
//是否结束while循环 v>]g="5}8
boolean breakWhile = false; c!ZZMCs
l8FJ\5'M
L5bq\
while(!bStop) x95s%29RS
{ o8R_Ojh
write_nPos(); i1cd9
Utility.sleep(500); l+9RPJD/:
breakWhile = true; @Chl>s
W3,r@mi^s7
c["1t1G
for(int i=0;i<nStartPos.length;i++) x4I!f)8Q
{ /o9it;
if(!fileSplitterFetch.bDownOver) gw)4P tb!
{ <=NnrZOF
breakWhile = false; J@2jx4
break; ` IVQ
} pTCD1)
} M{J>yN
if(breakWhile) 3gUY13C}:p
break; >%tP"x{
2nyK'k
e3ZRL91c
//count++; \6wltTW]#
//if(count>4) |HycBTN#E
// siteStop(); ZWCsrV*;
} y~+LzDV
@@D/&}#F
RnkV)ed(
System.err.println("文件下载结束！"); xw8k<`
} X%YZQc9
catch(Exception e){e.printStackTrace ();} }ppApJT
} { 4j<X5V
SD^::bH
?ES{t4"
//获得文件长度 C1;uAw?\
public long getFileSize() }ekNZNcuM
{ TgcCR:eL=
int nFileLength = -1; &`m.]RV
try{ `:iMGqZN
URL url = new URL(siteInfoBean.getSSiteURL()); /RB%m8@;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .V!5Ui<
httpConnection.setRequestProperty("User-Agent","NetFox"); dzIBdth
DNmC
=#2%[kGq
int responseCode=httpConnection.getResponseCode(); %`$bQU
if(responseCode>=400) `lY-/Ty
{ \*MZ1Q*x
processErrorCode(responseCode); <2(X?,N5BD
return -2; //-2 represent access is error !\'w>y7
} 1jx?zvE,
;ab[YMkH
A5R"|<UPR
String sHeader; gkK(7=r%
I]HYqI
J)g +I
for(int i=1;;i++) F42^Uoaz
{ i`i`Hu>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _Q #[IH9
//Utility.log(in.readLine()); s3Bo'hGxG
sHeader=httpConnection.getHeaderFieldKey(i); HxR5&o
if(sHeader!=null) -n@,r%`UK
{ -qSGa;PJ
if(sHeader.equals("Content-Length")) \)*\$I\]
{ Ks3YrKk;p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E7$ aT^
break; }G(#jOYk
} ZXhNn<
} =glG |
else *[>{9V
break; fhk(<KZvJ
} aAcQmq TT
} nVpDjUpN
catch(IOException e){e.printStackTrace ();} tv-SX=T
catch(Exception e){e.printStackTrace ();} 5bZ0}^FYF
di;~$rI!?
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Utility.log(nFileLength); /?>W\bP<
2x gk$E$7
2kgSIvk\
return nFileLength; Cf 202pF3y
} J^WX^".E
shLMj)7!
'QpDx&~QP
//保存下载信息（文件指针位置） 9QD+
private void write_nPos() ga'G)d3oS
{ #.FhN x
try{ }w=|"a|,
output = new DataOutputStream(new FileOutputStream(tmpFile)); $LBgBH&z
output.writeInt(nStartPos.length); IM,d6lN6s
for(int i=0;i<nStartPos.length;i++) 1q ZnyJ
{ i1{)\/f3
// output.writeLong(nPos); 3?k<e
output.writeLong(fileSplitterFetch.nStartPos); njNqUo>
output.writeLong(fileSplitterFetch.nEndPos); sCf)#6mI
} h1Y^+A_
output.close(); ZDmY${J
} 3]pHc)p!.
catch(IOException e){e.printStackTrace ();} MAL;XcRR
catch(Exception e){e.printStackTrace ();} kTm}VTr 1
} e. R9:
7Q?^wx
V}Ce3wgvA
//读取保存的下载信息（文件指针位置） L fZF
private void read_nPos() !iW>xo
{ c-ql
try{ |u+!CR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ur[^/lxx0
int nCount = input.readInt(); FzG>iC}
nStartPos = new long[nCount]; <4582x,G
nEndPos = new long[nCount]; ~re~Ys
for(int i=0;i<nStartPos.length;i++) k +Cwnp
{ es<
nStartPos = input.readLong(); xcH&B%;f
nEndPos = input.readLong(); =X7_!vSv
} a`>H69(bU
input.close(); #gXxBM
} 6i%Xf i
catch(IOException e){e.printStackTrace ();} \;JZt[
catch(Exception e){e.printStackTrace ();} )T^xDx
} pk0{*Z?@
>~_)2_j
~7m+N)5
private void processErrorCode(int nErrorCode) Z{1B:aW
{ 1:J+`mzpl
System.err.println("Error Code : " + nErrorCode); ^,aI2vC
} 'UM *7
G=|~SYz
ilAhw4A
//停止文件下载 3cF8DNh
public void siteStop() >T-4!ZvS\j
{ _PSOT5{
bStop = true; 5]n\E?V'L
for(int i=0;i<nStartPos.length;i++) $=) Pky-~
fileSplitterFetch.splitterStop(); 8[D"
l2I%$|)d
W2'!Pc,W
} D}Sww5ZmP
} z"Mk(d@-E
//负责部分文件的抓取 l>KkAA
**FileSplitterFetch.java $tej~xZK
*/ 2f620
package NetFox; bc3`x1)\^
+wf9!_'
[bRE=Zr$Ry
import java.io.*; # 1dg%
import java.net.*; MzDosr3:
Nd&UWk^
9zY6hh**
public class FileSplitterFetch extends Thread { X-#&]^d
pdvnpzj
!-%XrU8o3
String sURL; //File URL xF@&wg
long nStartPos; //File Snippet Start Position 'C]Yh."u
long nEndPos; //File Snippet End Position e.~11bx
int nThreadID; //Thread's ID gY8$Rk %
boolean bDownOver = false; //Downing is over _54gqD2C,
boolean bStop = false; //Stop identical kw E2V+2
FileAccessI fileAccessI = null; //File Access interface 8g Z)c\
lRb>W31"
M:b#">M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L9lJ4s
{ 4QTHBT+2`
this.sURL = sURL; ,Aai-AGG@
this.nStartPos = nStart; m uy^>2p
this.nEndPos = nEnd; o]RZd--c<
nThreadID = id; EO~L.E%W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }YVF fi~
} >7zC-3
Ikw@B)0}
cR_pC 9z
public void run() *BdH &U
{ ');vc~C
while(nStartPos < nEndPos && !bStop) _+'!l'`
{ DA.k8M
P_w4 DU
1^^8,.'
try{ ;RRw-|/Wm
URL url = new URL(sURL); "ayV8{m^3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X;N?L%Pp
httpConnection.setRequestProperty("User-Agent","NetFox"); yCvtglAJ4
String sProperty = "bytes="+nStartPos+"-"; !*Eu(abD
httpConnection.setRequestProperty("RANGE",sProperty); q\]X1N
Utility.log(sProperty); #79[Qtkrhm
^9:`D@Z+
.<F46?HS
InputStream input = httpConnection.getInputStream(); #Pp:H/b
//logResponseHead(httpConnection); ^n(FO,8c
FV/t
Z|%h-~
byte[] b = new byte[1024]; >Vjn]V5y
int nRead; kuD$]A Q`&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]LUcOR
{ xdgAu
nStartPos += fileAccessI.write(b,0,nRead); w9G|)UDib
//if(nThreadID == 1) R`Z"ey@C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A*?PH`bY
} rR-[CT
abQ.N
e;"J,7@
Utility.log("Thread " + nThreadID + " is over!"); Y?NL|cW4
bDownOver = true; Cl<!S`
//nPos = fileAccessI.write (b,0,nRead); {pIh/0
} g"1V]
catch(Exception e){e.printStackTrace ();} in<.0v9w
} zR?R,k)m
} b>OB}Is
L)J1yw
dX cbS<
//打印回应的头信息 )|xu5.F
public void logResponseHead(HttpURLConnection con) =JIceLL
{ @6>Q&GYqt
for(int i=1;;i++) qqf`z,u
{ !q\=e@j-i
String header=con.getHeaderFieldKey(i); BZ?3=S1*
if(header!=null) pqb'L]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DOKe.k
Utility.log(header+" : "+con.getHeaderField(header)); cQj`W *
else k8+J7(_c
break; I]v2-rB&-
} S@HC$
} at_*Zh(
YQG<Q
FfJ;r'eGs
public void splitterStop() EVX3uC}{
{ )OV0YfO
bStop = true; 5;/n`Bd
} !Zj]0,^
.P)lQk\
\Mg_Q$
} @./h$]6
,*XB11P
3}fOb
/* .d1ff];
**FileAccess.java 6WY/[TC-
*//文件访问(定位，写) ^~YT<cJ1h
package NetFox; Ik0g(-d
import java.io.*; 0hemXvv1
A9MM^jV8
10FiA;
public class FileAccessI implements Serializable{ ZZT #V%Q=u
H{*Dc_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b"h'7C/
RandomAccessFile oSavedFile; y!#-[K:
long nPos; FOXSs8"c]!
vV}w>Ap[
e3p|g]
public FileAccessI() throws IOException )!"fUz$
{ !RI _Uph
this("",0); jzbq{#
} ,dIev<
pZnp!!G
8q[; 0
public FileAccessI(String sName,long nPos) throws IOException K;RH,o1
{ &?@C^0&QV
oSavedFile = new RandomAccessFile(sName,"rw"); p~$cwbQ!
this.nPos = nPos; *LEy#N
oSavedFile.seek(nPos); e}UQN:1
} bF"l0 jS
%2}fW\%'
BO[:=x`
public synchronized int write(byte[] b,int nStart,int nLen) XnyN*}8
{ sey,J5?
int n = -1; za_b jE
try{ N6Mr#A-{
oSavedFile.write(b,nStart,nLen); +hyOc|5
n = nLen; UY',n,
} |[*Bn3E:
catch(IOException e) c7e,lgG-
{ Pxlc RF
e.printStackTrace (); r]3-}:vU
} j6m;03<|
WMB%?30
n#(pT3&
return n; en<~_|J
} #EPC]jFk
c[h~=0UtJ
]S6Gz/4aV+
} EW `hL~{
+,76|oMsQ%
=Hi@q "
/* .GrOdDK$ns
**SiteInfoBean.java 7r:h_r-
*/ Su#0F0
package NetFox; cQU/z"?+
EQ1**[$
xRh 22z
public class SiteInfoBean { V1aP_G-:
)^j_O^T5
"=h1gql'
private String sSiteURL; //Site's URL ula-o)S
private String sFilePath; //Saved File's Path rAenxZ,tF
private String sFileName; //Saved File's Name }9fa]D-a?
private int nSplitter; //Count of Splited Downloading File {r^_g(.q
*6Wiq5M>.
\[MAa:/
public SiteInfoBean() n]4E>/\
{//nSplitter的缺省值为5 LPvp (1
//default value of nSplitter is 5 dOhSqx56
this("","","",5); SQodk:1)
} {;yO3];Hqw
{2\Y%Y'}*
_#8hgwf>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -C=0Pg]ga
{ q}{E![ZTu
sSiteURL= sURL; _7Y h[I4
sFilePath = sPath; l]*RiK2AC
sFileName = sName; 6h:QSVfx
this.nSplitter = nSpiltter; t~Q9}+
W`>|OiuF
`|t,Uc|7!
} }[p{%:tP
[&lK.?V)
=ZgueUz,
public String getSSiteURL() +f3Rzx]
{ :qzg?\(
return sSiteURL; Xoj"rR9|
} RY-iFydPc
N`8K1{>BH
74%vNKzc~
public void setSSiteURL(String value) wuqe{?
{ 'HA{6v,y
sSiteURL = value; )2f#@0SVL
} (.J/Ql0Y
o[C^z7WG0
U8_{MY-9}
public String getSFilePath() yV^Yp=f_
{ eg[EFI.h
return sFilePath; [|nK5(e9
} 8Pn
9b. kso9.
Wf~^,]9N
public void setSFilePath(String value) ?t/qaUXN
{ /!6'K
sFilePath = value; oW^b,{~V
} +){^HC\7h
/}:{(Go
H%_^Gy8f
public String getSFileName() V)$!WPL@
{ &V38)83a
return sFileName; }">r0v!3
} FXCBX:LnvU
x ;DoQx
2BccE
public void setSFileName(String value) y0%@^^-Ru
{ }k-V(
sFileName = value; mWviWHK
} 1?'4%>kp
/~LE1^1&U
,np=m17
public int getNSplitter() Ww<Y]H$xZ<
{ h.<f%&)F
return nSplitter; ;c 7I "?@z
} `d <`>
NaR} 0
d) -(C1f
public void setNSplitter(int nCount) tU4#7b:Y
{ := V?;
nSplitter = nCount; -}7$;QK&a
} A7 RI&g v5
} 6[m~xegG
1W|jC
A mZXUb
/* GcO2oq
**Utility.java N{Sp-J>
*/ 80nEQT y
package NetFox; TQR5V\{&%
yP58H{hQM8
rPk|2l,E,3
public class Utility { c>bns/f
k_pv6YrE
lZk z\
public Utility() %A zy#m
{ 7Kw'Y8
Tm"H9
juEPUsE
} ~RR!~q
qda 2
//线程睡眠 Us`=^\
public static void sleep(int nSecond) ItVN,sVJb
{ ~&Z>fgOTJ
try{ N[Z`tk?-
Thread.sleep(nSecond); eo+<@83
} /WQ.,a
catch(Exception e) z:Am1B
{ 2@S}x@^
e.printStackTrace (); 9evr!=":
} TgkVd]4%
} %`]+sg[i
7uR;S:WX
//日志 \HGf!zZ
public static void log(String sMsg) ?L<B]!9HZt
{ mCO1,?
System.err.println(sMsg); &nEL}GM)E
} sq$v6x sl
bZ*=fdh
Odwe1q&
public static void log(int sMsg) _LJF:E5L
{ H07\z1?.K
System.err.println(sMsg); x2!R&q8U>
} v,<14w
} j_JY[sex
aAjl 58
svpQ.Q
/* m?w_ ]
**TestMethod.java =x<N+vjXY
*/ wI@87&
package NetFox; wm~7`&
"3RFyi
n&[CTOV
public class TestMethod { I=dG(?#7%
W3le)&
*(9Tl]w
public TestMethod() >9H^r\
{ ///xx/weblogic60b2_win.exe !|[rh,e]
try{ nH#>_R (
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $INB_/RE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .!3e$mhV
SiteFileFetch fileFetch = new SiteFileFetch(bean); ZJ3g,dc
fileFetch.start(); _=mzZe[
} >pF*unC;
catch(Exception e){e.printStackTrace ();} w<(ubR %$
*2h%dT:,%
i(4<MB1a
} \0)jWCK
1'&.6{)P
RqA>"[L
public static void main(String[] args) l5D)UO
{ B%tF|KKj
new TestMethod(); Ll]5u~
} H$%MIBz>$
} .~i|kc]Ue
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