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)); 4y 582u6^
} dHf_&X2A
for(int i=0;i<nEndPos.length-1;i++) rS(693kb
{ `j4ukOnG
nEndPos = nStartPos[i+1]; @YpA'cX7
} h5Qxa$Oq
nEndPos[nEndPos.length-1] = nFileLength; .HZYSY:X
} *1;<xeVD
} ^x4,}'(
)F4er'
.t"s>jq 1
//启动子线程 Qf>dfJ^q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *|euC"5c
for(int i=0;i<nStartPos.length;i++) (X>r_4W$
{ ms;Lu-UR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4"l(rg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bhe|q`1,E
nStartPos,nEndPos,i); I \vu?$w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kz,Nz09}W
fileSplitterFetch.start(); Sm+Ek@Ax
} lmr{Ib2a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y&'2/zI6~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q9%N>h9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VD36ce9
nEndPos = " + nFileLength); _e~EQ[,
// fileSplitterFetch[nPos.length-1].start(); <0R?#^XBZB
u^ngD64
: ]CZS
//等待子线程结束 Xg,E;LSF8
//int count = 0; >L&>B5)9
//是否结束while循环 7F|T5[*l
boolean breakWhile = false; 0p Lb<&
#Y`U8n2F
tTWYlbDFN
while(!bStop) VEb}KFyP
{ CCl*v
write_nPos(); t&0n"4$d'
Utility.sleep(500); A[oi?.D
breakWhile = true; 5f}63as
3.R?=npA
NwT3e&u%|
for(int i=0;i<nStartPos.length;i++) @*%5"~F
{ @zd)]O]xH?
if(!fileSplitterFetch.bDownOver) *e_ /D$SC
{ <]CO}r
breakWhile = false; tQ?? nI2
break; oB_{xu$6|
} Q6.},o
} U]e;=T:3
if(breakWhile) l6l)M
break; *<Qn)Az
=H!u4
LAMTf"a
//count++; g&BF#)7C
//if(count>4) Fm[,u
// siteStop(); =UTv
} *(o~pxFTR
\:-; {
_5.7HEw>/
System.err.println("文件下载结束！"); 1S.nqOfx
} 8@b@y|#]X
catch(Exception e){e.printStackTrace ();} (q:L_zFj>"
} mI"|^!L
6"jq/Pu
~Qzm!Po,
//获得文件长度 'Ur$jW
public long getFileSize() )W*S6}A
{ z4{|?0=C
int nFileLength = -1; Eer rIV
try{ v9M;W+J
URL url = new URL(siteInfoBean.getSSiteURL()); "hs`Y4U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /A<L
httpConnection.setRequestProperty("User-Agent","NetFox"); 2,NQ(c_c$
6PvV X*5T
kCN9`9XI{
int responseCode=httpConnection.getResponseCode(); \!G&:<h
if(responseCode>=400) @Cw<wrem
{ ,pf<"^li
processErrorCode(responseCode); &:'Uh W-t
return -2; //-2 represent access is error \J9@p
} oEKLuy
#W!@j"8eK
,/o<OjR
String sHeader; M@8 <^CK
ZIpL4y =_
H$1R\rE`
for(int i=1;;i++) lm]4zs /A
{ MK~viSgi
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /pX\)wi
//Utility.log(in.readLine()); e:!&y\'"9
sHeader=httpConnection.getHeaderFieldKey(i); t55 '
if(sHeader!=null) LA"`8
{ Bv!j.$0d{
if(sHeader.equals("Content-Length")) =AZ>2P
{ 9{xP~0g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); |910xd`Z
break; %4+r&
} FS`{3d2K +
} {T m-X`
else g4I(uEJk
break; *Pw;;#\B
} ,Qj7wFZ
} !:rQ@PSy9
catch(IOException e){e.printStackTrace ();} 8n);NZ
catch(Exception e){e.printStackTrace ();} IY,&/MCh
*>S\i7RET
Td"f(&Hk&
Utility.log(nFileLength); }2V|B4
3x'BMAA+
*Swb40L^
return nFileLength; b/5;377_
} /-G;#Wm
~G5)ya-
<\2,7K{{+;
//保存下载信息（文件指针位置） j"J2&Y2
private void write_nPos() M<g>z6
{ LuR.;TiW
try{ 9$UjZ$ v
output = new DataOutputStream(new FileOutputStream(tmpFile)); (K^9$w]tf
output.writeInt(nStartPos.length); VEo>uR
for(int i=0;i<nStartPos.length;i++) R}>Gk
{ BE}lzn=sF
// output.writeLong(nPos); N7}.9%EV
output.writeLong(fileSplitterFetch.nStartPos); N<Ti[Q]G
output.writeLong(fileSplitterFetch.nEndPos); !t~S.`vF
} 3vNoD
output.close(); |2{y'?,
} Mq6.!j
catch(IOException e){e.printStackTrace ();} .CrahV1G
catch(Exception e){e.printStackTrace ();} :m^eNS6:
} C!RxMccTh
GwW!Q|tVz=
im4V6 f;%
//读取保存的下载信息（文件指针位置） YX!%R]c%
private void read_nPos() sT'wps2
{ 1&Nk
try{ 4vp,izNW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _@jl9<t=_
int nCount = input.readInt(); WR gAc%
nStartPos = new long[nCount]; ,MuLu,$/
nEndPos = new long[nCount]; kJHUaXM
for(int i=0;i<nStartPos.length;i++) $*L@ym
{ J3y5R1?EP
nStartPos = input.readLong(); d!e$BiC
nEndPos = input.readLong(); Gzc{2"p
} osPX%k!yw
input.close(); )bw^!w)
} q ( H^H
catch(IOException e){e.printStackTrace ();} 9'td}S
catch(Exception e){e.printStackTrace ();} Ny p5=
} %HwPOEJ
y%`^*E&
6hAeLlU1
private void processErrorCode(int nErrorCode) mY#[D;mUe
{ e=1&mO?
System.err.println("Error Code : " + nErrorCode); jO<K0cc
} qRTxg%
s1:UCv-%
$zyY"yWRZ
//停止文件下载 <yE(p
public void siteStop() 0[);v/@Ho
{ s|%mGt &L
bStop = true; qW$IpuK
for(int i=0;i<nStartPos.length;i++) Y'%sA~g
fileSplitterFetch.splitterStop(); AX<TkS@wjb
E;| q
kO~xE-(=
} 2,E&}a|;b
} Pm%ZzU
//负责部分文件的抓取 h,rGa\X~0
**FileSplitterFetch.java T_y 'cvh
*/ 6=MejT
package NetFox; P[% W[E<
86vk"
Rfeiv
import java.io.*; fPZBm&`C
import java.net.*; qYGnebn@\
MU-ie*+
E6y/,s^~S_
public class FileSplitterFetch extends Thread { (ZT*EFhb(
;BejFcb
\*v}IO>2})
String sURL; //File URL 8!4=j
long nStartPos; //File Snippet Start Position )}]<o |'
long nEndPos; //File Snippet End Position {jJUS>
int nThreadID; //Thread's ID {~[H"h537t
boolean bDownOver = false; //Downing is over IP-CN
boolean bStop = false; //Stop identical #:DDx5%x<b
FileAccessI fileAccessI = null; //File Access interface Ajs<a(,6
It(8s)5
KaBze67<|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @@'zMV%
{ wvp\'* $
this.sURL = sURL; hc`9Y
this.nStartPos = nStart; C W7E2 ^P$
this.nEndPos = nEnd; A5F< <
nThreadID = id; 3@XCP-`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9kH~+
} 7.hVbjy'-
S%kE<M?
rs=wEMq/
public void run() 3!Rb{
{ &s\$&%|
while(nStartPos < nEndPos && !bStop) #fzvK+
{ rRYP~ $c
(GMKIw2
G0^23j
try{ Y^2`)':
URL url = new URL(sURL); {!o-y=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B.'@~$
httpConnection.setRequestProperty("User-Agent","NetFox"); 43A6B
String sProperty = "bytes="+nStartPos+"-"; .hSacd
httpConnection.setRequestProperty("RANGE",sProperty); z%`Tf&UL
Utility.log(sProperty); 1LJ ?Ka[_*
V4l`Alr\L
[WRs1$5
InputStream input = httpConnection.getInputStream(); ryW1OV6?_0
//logResponseHead(httpConnection); V%<<Udu<
fP&F$"o8
d[kb]lC
byte[] b = new byte[1024]; *P61q\2Z
int nRead; yodJGGAzk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4+$<G/K
{ ;=5V)1~i1;
nStartPos += fileAccessI.write(b,0,nRead); NQ'^z
//if(nThreadID == 1) B5 C]4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?0DCjh8We
} #fk)Y1
,B5Ptf#
0{BPT>'
Utility.log("Thread " + nThreadID + " is over!"); ^ B=x-G.
bDownOver = true; v"F.<Q
//nPos = fileAccessI.write (b,0,nRead); dt',)i8D
} one^XYy1%
catch(Exception e){e.printStackTrace ();} _B8e1an
} 9RE{,mos2v
} mkk74NY
c1jHg2xim
{,]BqFXv
//打印回应的头信息 /A9Mv%zjk
public void logResponseHead(HttpURLConnection con) nbMH:UY,J
{ {l0;G)-
for(int i=1;;i++) rPaD#GA[7
{ #E{aN?_
String header=con.getHeaderFieldKey(i); 6mep|![6
if(header!=null) +LV'E#h!Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2GqPS
Utility.log(header+" : "+con.getHeaderField(header)); 28f-8B
else &VY;Al
break; =<O{t#]
} kZU8s'C
} `]LaX&u
>BrxJw#M
E&{*{u4
public void splitterStop() `yP-,lA$
{ 0k:&7(j
bStop = true; @E,{p"{
} 8MX/GF;F
`RthX\Tof
F}H!vh[
} SjtGU47$!
?OZbns~
S4qh8c
/* O.TFV.
**FileAccess.java JV36@DVQ
*//文件访问(定位，写) c5;YKON
package NetFox; cuq7eMG6z
import java.io.*; Y@9L8XNP>
@!0j)5%
g"(N_sv?
public class FileAccessI implements Serializable{ pcur6:8W!
c*RZbE9k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K[~Wj8W0
RandomAccessFile oSavedFile; g#9w5Q
long nPos; pqMvYF
nI2}E
[cXu<vjFM
public FileAccessI() throws IOException g_0"T}09(
{ tborRi)
this("",0); n\,TW&3
} wS``Q8K+dM
~q4DePVE
<Ks?g=K-
public FileAccessI(String sName,long nPos) throws IOException eb9qg.9Z
{ Pk8L-[&v
oSavedFile = new RandomAccessFile(sName,"rw"); 2*K0~ b`
this.nPos = nPos; 0qG[hxt%
oSavedFile.seek(nPos); ^>%=/RX
} KS*W<_I
5\R8>G~H
?aOR ^ K
public synchronized int write(byte[] b,int nStart,int nLen) + {a
{ 45kMIh~~X
int n = -1; R3?~+y&
try{ Vq9hAD|k
oSavedFile.write(b,nStart,nLen); o&(%:|
n = nLen; ni2H~{]z
} 82O`<Ci
catch(IOException e) "MoV*U2s,
{ "5{Yn!-:
e.printStackTrace (); LTzf&TZbx5
} ^ / f*5k
2<ef&?ljk
/R|"/B0
return n; 1 _5[5K^
} C>T6{$xkC
<>j,Q
*zX<`E
} 'kH#QO\(e"
{H])Fob
PDD` eK}Fj
/* *k+QX
**SiteInfoBean.java 6b<t|zb
*/ AQQj]7Y
package NetFox; &cpRB&bf
sv0kksj
`Z%XA>
public class SiteInfoBean { zN2sipJS8
)B}]0`z:P
1+y&n?
private String sSiteURL; //Site's URL \F1nEj
private String sFilePath; //Saved File's Path Rx`0VQ
private String sFileName; //Saved File's Name QO#ZQ~
private int nSplitter; //Count of Splited Downloading File l\$C)q6O
QRdb~f;<hj
i3e|j(Gs4
public SiteInfoBean() *,'"\n
{//nSplitter的缺省值为5 t8?+yG;
//default value of nSplitter is 5 []dRDe;#
this("","","",5); c#HocwP@
} 5~rs55W
$<ZX};/D
0HNe44oI+D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fcw\`.
{ KpwUp5K
sSiteURL= sURL; ?[m5|ty#
sFilePath = sPath; Llk`
sFileName = sName; PY>j?otD
this.nSplitter = nSpiltter; E+~~d6nB
jWU)y)$
?nt6vqaV
} $mlsFBd
=A!I-@]q<
57[O)5u.+
public String getSSiteURL() JRodYXjE
{ l
return sSiteURL; 58v5Z$%--
} VKR6i
0hNc#x6
pn =S%Qf]
public void setSSiteURL(String value) ,9A[o`b
{ `q xg
sSiteURL = value; 'fVk1Qj^
} 5@v!wms
7XwFO0==
~z< ? Wh
public String getSFilePath() SnXYq7`t
{ F[?t"d
return sFilePath; Pt1Htt:BE
} aqyXxJS8
P,>#
Wg$MKc9Vy[
public void setSFilePath(String value) pkxW19h*0
{ -7pZRnv
sFilePath = value; l[.pI];T
} !MGQ+bD6
Y.}n,y|J}
"arbUX~d
public String getSFileName() gqC:r,a
{ i\t4TdEx(
return sFileName; nKHyq\
} ?VzST }
L~0B
SgY>$gP9S
public void setSFileName(String value) JgxOxZS`@
{ IGbQ L
sFileName = value; J7l1-
} ZM)a4h,kcm
TI*uNS;-
UnO -?
public int getNSplitter() n=yFw\w'
{ s\ ~r 8
return nSplitter; YHAy+S
} `GSfA0?
\y0abxIHS
( E0be.
public void setNSplitter(int nCount) k@wxN!w;
{ zb9$
nSplitter = nCount; 7%?A0%>6G
} yt<K!=7&
} ^ 5UIbA(
Qb SX'mx<
4W1"=VL[g
/* |\b*p:el
**Utility.java K(Cv9YQ
*/ /[us;=CM
package NetFox; $Itehy
my*/MC^O
k'S/nF A
public class Utility { &PGU%"rN
g.,IQ4o
,7/N=mz
public Utility() q'1rSK
{ EmH2 Dbw
yCmiW %L4
X#pE!mT
} OP>'<FK
fwOvlD&e
//线程睡眠 ]^.#d
public static void sleep(int nSecond) >S!QvyM(V
{ ^Ji5)c
try{ ,c7 8O8|
Thread.sleep(nSecond); rt."P20T
} Z!ub`coV[
catch(Exception e) SFh6'v'1N@
{ Z,Q)\W<'-
e.printStackTrace (); R[Pyrs!H
} q,+d\-+
} N.3M~0M*
}9@,EEhg
//日志 }t]CDa_n
public static void log(String sMsg) s K s D
{ /<M08ze
System.err.println(sMsg); >0u4>=#
} \5O4}sm$*
r0hu?3u1?
xy[R9_V
public static void log(int sMsg) #,$d!l @
{ jtN2%w;
System.err.println(sMsg); RELLQpz3
} CxwZ$0
} S^~GI$
;JDxl-~
=cg0o_q8
/* 1'Kn:I
**TestMethod.java ,qt9S0QS
*/ ,AWN *OS
package NetFox; {6A3?q
Rsqb<+7
ULAAY$o@5
public class TestMethod { nV GrW#'E
3C2L _ K3
RV7l=G9tq
public TestMethod() 8g&uCv/Uk
{ ///xx/weblogic60b2_win.exe NCd_h<}|6F
try{ MSsboSxA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ] S]F&B M|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >*dqFZF
SiteFileFetch fileFetch = new SiteFileFetch(bean); t|d9EC]c(
fileFetch.start(); @ Al\:
} ?MyXii<a
catch(Exception e){e.printStackTrace ();} e=TB/W_
b6Dve]
kW5g]Q
} =A04E
[v#t
(|"KsGl
public static void main(String[] args) b`fPP{mG
{ X>=`{JS1
new TestMethod(); _KC()OIeC
} B&`#`]
} dz&8$(f,
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