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)); ",&#9
} Va,M9)F
for(int i=0;i<nEndPos.length-1;i++) "H\'4'hg
{ Bi2be$nV
nEndPos = nStartPos[i+1]; ;%P$q9*C
} sL|lfc'bB
nEndPos[nEndPos.length-1] = nFileLength; wP3_RA]z
} Tyt:Abym=
} BUB#\v#a
eSf e s
q/-8sO}q
//启动子线程 }7YDe'5V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z:<mgp&/<
for(int i=0;i<nStartPos.length;i++) [q]"_4L0;d
{ A,D67G<v`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6T{Zee
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z#YkAQHv5
nStartPos,nEndPos,i); ! )$ PD@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V0+D{|thh6
fileSplitterFetch.start(); |$@/ Z+
} flp<QT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D7cOEL<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); z!27#gbL
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Gs%IZo_
nEndPos = " + nFileLength); ""l_&3oz
// fileSplitterFetch[nPos.length-1].start(); ]z`Y'wSxd
xMJF1O?3
+cv7]
//等待子线程结束 ;Vc@]6Ck
//int count = 0; 6dQa|ACX_
//是否结束while循环 Icf 4OAx
boolean breakWhile = false; #+Z3!VS
2xRb$QF
uV.3g 1m
while(!bStop) ?PORPv#
{ eA9U|&o
write_nPos(); <Ur(< WTV
Utility.sleep(500); E< nXkqD
breakWhile = true; fo~8W`H&
<e"O`*ZJ
yO.3~H)c
for(int i=0;i<nStartPos.length;i++) +;SQ}[
{ o<P@:}K
if(!fileSplitterFetch.bDownOver) a*JM2^,HO
{ |,M&ks
breakWhile = false; r*]0PQ{?
break; lQQXV5NV
} x bF*4;^SI
} b2c% 0C
if(breakWhile) Ry*NRP;
break; -}|GkTM
|qbCmsY5/
i$[wgvJIV
//count++; Xm`s=5%
//if(count>4) 6ae
// siteStop(); ]$(::'pmK
} m)9N9Ii#)
rZ<0ks
>kOca
System.err.println("文件下载结束！"); 'TpW-r:
} l!e8=QlJ
catch(Exception e){e.printStackTrace ();} l=*^FK]L`
} |sz`w^#
Ib.`2@o&
'JY*K:-
//获得文件长度 n m(yFX?=
public long getFileSize() hH:7
{ TN3, \qgV
int nFileLength = -1; 8}h ^Frh
try{ h-hU=I8
URL url = new URL(siteInfoBean.getSSiteURL()); hKjvD.6]%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6'ye-}vD-
httpConnection.setRequestProperty("User-Agent","NetFox"); WmLl.Vv=
Pi::cf>3
Yu=4j9e_mG
int responseCode=httpConnection.getResponseCode(); vfzGRr
if(responseCode>=400) >R3~P~@30
{ _H^Ij
processErrorCode(responseCode); 6~GaFmW=
return -2; //-2 represent access is error ;>[).fX>/
} pW O-YZ#+
=Xzqp,
f ^mxj/%L
String sHeader; 8,2l >S
d}tn/Eu?B
B#o(21s
for(int i=1;;i++) Dr6"~5~9w
{ OO_{o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LA$uD?YA
//Utility.log(in.readLine()); 3P Twpq1
sHeader=httpConnection.getHeaderFieldKey(i); 0K7]<\)
if(sHeader!=null) pVn6>\xa
{ lqAU5K{wQ
if(sHeader.equals("Content-Length")) USu/Y29
{ (FZL>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E>TD`
break; m s\:^a
} 6"WR}S0o
} A=|LMJMWR
else l;U9dO}/[
break; JGt4B
} 'GQ1;9A57
} vq_W zxaG
catch(IOException e){e.printStackTrace ();} a{Y:hrd:Z
catch(Exception e){e.printStackTrace ();} DCX4!,ZF
@I}:HiF
>=^g%K$L6J
Utility.log(nFileLength); mU:C{<Z
tp$NT.z
>#dNXH]9
return nFileLength; Q6Q>b4 .3
} R6dw#;6{I
=%Gecj
n|NI]Qi*
//保存下载信息（文件指针位置） R?1;'pvpa[
private void write_nPos() X obiF
{ $f>Mz|j
try{ W-=~Afy
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^te9f%>$l
output.writeInt(nStartPos.length); CZE5RzG
for(int i=0;i<nStartPos.length;i++) t)g1ICt
{ Zb-TCS+3l
// output.writeLong(nPos); f[ GH
output.writeLong(fileSplitterFetch.nStartPos); MUz.-YRt
output.writeLong(fileSplitterFetch.nEndPos); oLk>|J
} a}`4BMi3
output.close(); +^<CJNDL9
} hF+YZU]rT
catch(IOException e){e.printStackTrace ();} \l_RyMi
catch(Exception e){e.printStackTrace ();} .rSeJZzuj
} ] =b?^'
:Y y+%
al=Dy60|z
//读取保存的下载信息（文件指针位置） bj(U?$
private void read_nPos() kxoJL6IC
{ O(,Ezyx
try{ ru3nnF_I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m\U@L+L
int nCount = input.readInt(); ?nrd$,
nStartPos = new long[nCount]; ^C>i(j&
nEndPos = new long[nCount]; ;E:ra_l
for(int i=0;i<nStartPos.length;i++) ?v#t{e0eQ
{ MR%M[SK1
nStartPos = input.readLong(); Rb<aCX
nEndPos = input.readLong(); 3s\2 9gq
} !40{1U&@a`
input.close(); LYGFEjS[
} V!c{%zd
catch(IOException e){e.printStackTrace ();} {"y{V
catch(Exception e){e.printStackTrace ();} QV+('
} G9z Q{E
\%&QIe;:k
g6Qzkvw)
private void processErrorCode(int nErrorCode) :g'"*VXYB
{ Y%p"RB[
System.err.println("Error Code : " + nErrorCode); tbAN{pX
} {i~qm4+o
a~OCo
CY)Wuv ^
//停止文件下载 ~t<BZu
public void siteStop() ;W?e@ Lgxk
{ 2{"Wa|o`
bStop = true; 8l>/ZZ.NXi
for(int i=0;i<nStartPos.length;i++) LGK0V!W
fileSplitterFetch.splitterStop(); [[JwHM8H&
%&Z!-k(
!rb)Y;WQt
} J\_tigd
} !-x^b.${B
//负责部分文件的抓取 VyCBJK
**FileSplitterFetch.java .zlUN0oe
*/ N-3w)23*:
package NetFox; h_?D%b~5
h\C
|=l;UqB
import java.io.*; -DX|[70
import java.net.*; Y!i4P#4+q
e.\d7_T+
Hh$D:ZO
public class FileSplitterFetch extends Thread { |g> K$m^
fcr\XCG7U
!K'kkn,h
String sURL; //File URL :b^tu8E
long nStartPos; //File Snippet Start Position (BMFGyE3
long nEndPos; //File Snippet End Position Cf<i"
int nThreadID; //Thread's ID ~c! XQJ
boolean bDownOver = false; //Downing is over p8[Z/]p
boolean bStop = false; //Stop identical U;;vNzcn
FileAccessI fileAccessI = null; //File Access interface n0O- Bxhl
bY+Hf\A
}_3<Q\j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException JmWN/mx
{ pb$U~TvzhM
this.sURL = sURL; -78 t0-lM
this.nStartPos = nStart; `P)atQ
this.nEndPos = nEnd; _R]la&^2F\
nThreadID = id; rxIfatp^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *7nlel
} <bXfjj6YJ@
"1&C\}.7
#]:yCiA
public void run() TTmNPp4q
{ `DC)U1
while(nStartPos < nEndPos && !bStop) zvdtP'&uj
{ ~(-B%Az
rh${pHl
3VB{Qj
try{ $eX; 2
URL url = new URL(sURL); 4tCyd5u a8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m-5Dbx!j
httpConnection.setRequestProperty("User-Agent","NetFox"); zYYc#N/
String sProperty = "bytes="+nStartPos+"-"; E>KV1P
httpConnection.setRequestProperty("RANGE",sProperty); IBQmm(+v
Utility.log(sProperty); Ts|&_|
syv6" 2Z'B
Xko[Z;4v8'
InputStream input = httpConnection.getInputStream(); dW,$yH_
//logResponseHead(httpConnection); opjrU$<]N
NL0X =i
"npj%O<bd
byte[] b = new byte[1024]; My:wA;#
int nRead; 1r\? uD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LC*@/((
{ 2y,NT|jp
nStartPos += fileAccessI.write(b,0,nRead); mj%Iow.
//if(nThreadID == 1) }Wn6r_:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?#rDoYt/Sx
} $wdIOfaH
Q^DKKp
c3`X19'%fM
Utility.log("Thread " + nThreadID + " is over!"); ka[]pY
bDownOver = true; zRD{"uqi
//nPos = fileAccessI.write (b,0,nRead); z4&|~-m,
} (JL{X`gs#
catch(Exception e){e.printStackTrace ();} y2TJDb1
} PC7U&*x@
} * "~^k^_b}
31 QT
`Q,moz
//打印回应的头信息 Qi w "x,
public void logResponseHead(HttpURLConnection con) *9`@
{ SH<Nt[8C
for(int i=1;;i++) #QXB2x<*
{ +K; X$kB
String header=con.getHeaderFieldKey(i); tegLGp@_
if(header!=null) oZmni9*SD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *t3fbD
Utility.log(header+" : "+con.getHeaderField(header)); c9=;:E
else p3\F1](Z
break; A>bo Xcr
} UCa(3p^V_
} 3!Gnc0%c
n*9)Y~
Z'/:
public void splitterStop() ]Yp;8#:1
{ `CUTb*{`
bStop = true; }RO Cj,|
} :&/'rMi<T
,~hvFTJI
&+xNR2";
} p4fU/
|/Ggsfmby
(VI4kRj
/* *A@~!@XE4
**FileAccess.java /Pxt f~$
*//文件访问(定位，写) *=$Jv1"Q +
package NetFox; bsmZR(EnU
import java.io.*; Cz+`C9#
X) owj7U;
NJI-8qTGI
public class FileAccessI implements Serializable{ q#xoM1
GASDkVoij
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $GSn#} yz
RandomAccessFile oSavedFile; ^Cst4=:W
long nPos; !.?2zp~
quTM|>=_R
& VJ+X|Z
public FileAccessI() throws IOException [W,Ej
{ i ?%;s5<
this("",0); d!D#:l3;
} >KNiMW^V
]t=m
LS}u6\(
public FileAccessI(String sName,long nPos) throws IOException 5hr$tkkL
{ L09YA
oSavedFile = new RandomAccessFile(sName,"rw"); ||;V5iR:
this.nPos = nPos; 0>6J-
oSavedFile.seek(nPos); @a'Rn
} P6!c-\
[o<Rgq4
dzjp,c@
public synchronized int write(byte[] b,int nStart,int nLen) \'xF\V
{ /vYuwaWG=
int n = -1; l:-$ulAx
try{ 3,8<5)ds*
oSavedFile.write(b,nStart,nLen); ]]Sz|6P
n = nLen; %?Yf!)owh
} w<!F& kQB
catch(IOException e) V8@VR`!'
{ fZw/kjx@
e.printStackTrace (); p9 <XaJ}
} 1Mn=m w
DI{VJ&n66
E z?O gE{
return n; Iq]+O Q
} -y|>#`T/
)"/.2S;
v-B{7 ~=#Z
} mSm:>hBd
U>H"N1
r7+"i9
/* F0t-b%w,
**SiteInfoBean.java I<L
*/ Y``50{7
package NetFox; xAbx.\
uD0T()J.P5
e{EKM4
public class SiteInfoBean { wj!YYBH
A=JPmsj.
{$-lXw4
private String sSiteURL; //Site's URL (HbA?Aja
private String sFilePath; //Saved File's Path 9AF%Y:y
private String sFileName; //Saved File's Name S~()A*5
private int nSplitter; //Count of Splited Downloading File :[xFp}w{
uH="l.u
F$.h+v
public SiteInfoBean() Rsd~t_a1
{//nSplitter的缺省值为5 |(u6xPs;P
//default value of nSplitter is 5 <|8N\FU{
this("","","",5); 1Bp?HyCR
} q4=Gj`\43
*eL&fC
@rI+.X
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NXo$rf:
{ 4zKmoYt
sSiteURL= sURL; hGh91c;4
sFilePath = sPath; OIJNOuI
sFileName = sName; eocq Hwbv
this.nSplitter = nSpiltter; ;}1O\nngR
/|Z_Dy
) rw!. )
} xs,,)jF(u
CoZOKRoaH
o]/*YaB2>
public String getSSiteURL() >n$V1U&/
{ ^x2zMB\t
return sSiteURL; NH9"89]E
} 3MX&%_wUhB
n x4:n@J
U/}YpLgdD
public void setSSiteURL(String value) 0OCmyy
{ PtsQV!
sSiteURL = value; RGEgYOO
} +*uaB
9UDanj P
\.ukZqB3 0
public String getSFilePath() f|f)Kys%5
{ W%@r
return sFilePath; eF-U 1ZJT
} R&.mNji*
fVf @Ngvu
|2ImitN0
public void setSFilePath(String value) ['m7Wry
{ $,u>,
sFilePath = value; *!oV?N[eA'
} Yo%ph%e
HpP82X xj
&?g!)O
public String getSFileName() ;P *`v
{ mHe[ NkY6
return sFileName; ba-4V8w
} !E7JDk''@
U45kA\[bZ
FD'yT8]"
public void setSFileName(String value) cl04fqX
{ gcF:/@:Rm
sFileName = value; Upw`|$1S
} 9]C%2!Ur,
B/O0 ~y!n
"w&IO}j;=
public int getNSplitter() Oh# z zo
{ |xawguJ
return nSplitter; )_n=it$
} &cGa~#-u
?}RPnf
+>3jMs~&
public void setNSplitter(int nCount) [s4|+
{ tn{YIp
nSplitter = nCount; :a/l9 m(
} ONVhB
} y%Rq6P=4Q
hsB3zqotF
`%A vn<
/* ]A%]W^G
**Utility.java fn#qcZv?
*/ mUj_V#v
package NetFox; PctXh, =
"7q!u,u
P{,A%t
public class Utility { E)%DLZ
+pPfvE`
ee/3=/H|;
public Utility() `^ZhxFX
{ Um^4[rl:#g
9;7Gzr6A"
O!!N@Q2g
} '8Cg2v5&w
=kTHfdin&
//线程睡眠 qxB|*P`
public static void sleep(int nSecond) gLm,;'h%u
{ x8w l
try{ 2##;[
Thread.sleep(nSecond); *8r^!(Kj
} f$76p!pDa
catch(Exception e) Vy=P*
{ 3n,jrX75u
e.printStackTrace (); cO$xT;kK
} |k$6"dXSO
} P!Brw72
)SZzA'
//日志 QLH!>9Ch
public static void log(String sMsg) !RP0W
{ \o*w#e[M
System.err.println(sMsg); qjObu\r
} q68CU~i*
U&i#cF
oam$9 q
public static void log(int sMsg) yg.o?eML
{ ~&?57Sw*m
System.err.println(sMsg); X J`*dgJ
} Xdi<V_!BC-
} qV9}N-sS
$PG(>1e
\ZM5J
/* vw 6$v
**TestMethod.java cLEd-{x
*/ -4[eZ>$A|
package NetFox; 4E2#krE%
(gnN</%
Atb`Q'Yrw
public class TestMethod { K@<*m!%<2
_TLspqi
Nw9@E R
public TestMethod() E[WU
{ ///xx/weblogic60b2_win.exe #.rkvoB0N
try{ kebk f,`p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W[I$([
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i=L 86Ks
SiteFileFetch fileFetch = new SiteFileFetch(bean); x <a}*8"
fileFetch.start(); I{Ip
} :tBe/(e4#
catch(Exception e){e.printStackTrace ();} )RN3Oz@H
0cSm^a
vh.-9eD
} Zb=;\l*&
MJh.)kd$
_CPj]m{
public static void main(String[] args) cRH(@b Xr
{ sj4\lpZ3h
new TestMethod(); L pq)TE#
} 43E)ltR=]
} `*cqT
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