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)); [AIqKyIr
} 9m_~Zs}Z
for(int i=0;i<nEndPos.length-1;i++) nQ|($V1?W
{ Y`$\o
nEndPos = nStartPos[i+1]; LfU? 1:Du
} xe(7q1
nEndPos[nEndPos.length-1] = nFileLength; I`jG
} iqB%sIP
} tQxxm=>
$_eJ@L#
E+e),qsbO
//启动子线程 |=~mRqG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lfd-!(tXD
for(int i=0;i<nStartPos.length;i++) v$JW7CKA
{ #h9Gl@|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t;PG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8'qlg|{!~
nStartPos,nEndPos,i); w@6y.v1I{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .!lLj1?p
fileSplitterFetch.start(); a+O?bO
} 73]t5=D:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o$U{.#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S1~K.<B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m J$[X
nEndPos = " + nFileLength); r| \""
// fileSplitterFetch[nPos.length-1].start(); y] O&w{m$
Fo%`X[?
#4"eQ*.*"
//等待子线程结束 zLg$|@E&
//int count = 0; 5.oY$tb(
//是否结束while循环 gcO$T`
boolean breakWhile = false; & @_PY
Ku uiU= (L
|yp^T
while(!bStop) )Spa F)N8
{ (]&B'1b
write_nPos(); "cjD-42
Utility.sleep(500); Zy?!;`c*{
breakWhile = true; GNB'.tJ:0Y
:9x]5;ma
*uccY_
for(int i=0;i<nStartPos.length;i++) f w)tWJVD
{ ]c|JxgU
if(!fileSplitterFetch.bDownOver) VQ2'a/s
{ GiK,+M"d
breakWhile = false; aZa1eE
break; $[Nf?`f(t_
} )"{}L.gC6
} }vgM$o
if(breakWhile) +;pw^QB
break; pzQc UG
nox-)e
saQo]6#
//count++; iyUnxqP
//if(count>4) ,+C?UW
// siteStop(); (G$Q\>
} =,qY\@fq
eOXu^M>:F
:=!6w
System.err.println("文件下载结束！"); b KDD29
} 'gD./|Z0
catch(Exception e){e.printStackTrace ();} gVJh@]8)
} "WXUz
-?{g{6
pX!T; Re;
//获得文件长度 [0kZyjCq@
public long getFileSize() QG L~??
{ 4OO^%`=)M'
int nFileLength = -1; {9j0k`A
try{ P%vouC0W
URL url = new URL(siteInfoBean.getSSiteURL()); ZnRj}y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @7Ln1v
httpConnection.setRequestProperty("User-Agent","NetFox"); >Lo'H}[pF
.A6pPRy e
9asA-'fZ
int responseCode=httpConnection.getResponseCode(); H0t#J
if(responseCode>=400) -=UvOzw
{ `jhbKgR[
processErrorCode(responseCode); ~+Cl9:4T
return -2; //-2 represent access is error Ic&YiATj
} IeA/<'Us
Ro<5c_k
L>hLYIW
String sHeader; };Df ><
7`)RBhGB
3|)cT1ej
for(int i=1;;i++) A5 4u}
{ j!;E>`g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ma) + G!
//Utility.log(in.readLine()); ~]<VEji
sHeader=httpConnection.getHeaderFieldKey(i); a?Y>hvI
if(sHeader!=null) }&s |~
{ )MoHY
if(sHeader.equals("Content-Length")) :iQJ9Hdz
{ ~% `hh9]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9ku|w#%I
break; vtK.7AF
} >>y\idg&:
} ]z=dRq
else YbZ?["S&
break; 3Y +;8ld
} tF<&R&=
} gdyWuOxa|
catch(IOException e){e.printStackTrace ();} Zm6jF
catch(Exception e){e.printStackTrace ();} 'r-B%D=
W&I:z-VH
GGZ9DC\{
Utility.log(nFileLength); auY?Cj'"fs
]1h9:PF
I?\P^f
return nFileLength; v9f%IE4fX
} z`u$C+Ov
:zO;E+s
!g|[A7<|
//保存下载信息（文件指针位置） :qShP3^
private void write_nPos() wLE|J9t%Ea
{ o{hZjn-
try{ v=&xiwz}
output = new DataOutputStream(new FileOutputStream(tmpFile)); mOyNl -f
output.writeInt(nStartPos.length); Ar_Yl|a
for(int i=0;i<nStartPos.length;i++) W%9~'pXgB
{ )lUocm
// output.writeLong(nPos); @|OGxQoC
output.writeLong(fileSplitterFetch.nStartPos); ! 8Ro5),
output.writeLong(fileSplitterFetch.nEndPos); cmd7-2
} "s`#`'
output.close(); #0^a-47PA<
} N?A}WW#
catch(IOException e){e.printStackTrace ();} K,P`V &m?
catch(Exception e){e.printStackTrace ();} C&EA@U5X^
} AnZy oa
~~p)_
}<'ki ;
//读取保存的下载信息（文件指针位置） 4Y G\<Zf
private void read_nPos() {8%KO1xB
{ !SLfAFcS
try{ oIE3`\xS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \"5p)(
int nCount = input.readInt(); =dWqB&
nStartPos = new long[nCount]; ^0(D2:E
nEndPos = new long[nCount]; ChNT;G<6$
for(int i=0;i<nStartPos.length;i++) ,d^HAg^j
{ ;vk>k0S
nStartPos = input.readLong(); /7.//klN
nEndPos = input.readLong(); +*eVi3
} 9%MgAik(
input.close(); $}0\sj%
} nVP|{M
catch(IOException e){e.printStackTrace ();} |gT8QP
catch(Exception e){e.printStackTrace ();} R"z}q(O:
} (~"#=fs.L
:#N]s
T/hz23nH
private void processErrorCode(int nErrorCode) #.,LWL]
{ q+?q[:nR-
System.err.println("Error Code : " + nErrorCode); Y%zWaH
} ;1r|Bx<5
}`76yH^c
\t=#MzjR
//停止文件下载 .^ba*qb`{
public void siteStop() >Wd_?NaI
{ ^7*zi_Q
bStop = true; W}Rzn
for(int i=0;i<nStartPos.length;i++) UMPW<>z
fileSplitterFetch.splitterStop(); /(%!txSNEt
CRNt5T>qH
C_h$$G{S(
} '@^mesMG
} \r3SvBwhFv
//负责部分文件的抓取 cF"}}c1*M
**FileSplitterFetch.java <:StZ{o;
*/ 4#B56f8
package NetFox; wkJ@#jD*[
(7??5gjh
sv6m)pwh
import java.io.*; |#(y?! A^
import java.net.*; cCG!X%9
7eFFKl
^=gN >xP
public class FileSplitterFetch extends Thread { oC3W_vH.%
Juk'eH2^s
L/N%ft]!T
String sURL; //File URL #3FsK
long nStartPos; //File Snippet Start Position O6\c1ha
long nEndPos; //File Snippet End Position A":cS }Ui
int nThreadID; //Thread's ID v*OT[l7
boolean bDownOver = false; //Downing is over ))7CqN
boolean bStop = false; //Stop identical bq}`jP~#
FileAccessI fileAccessI = null; //File Access interface Vw&#Lo
)3 '8T>^<K
J7kqyo"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7oCY@>(f
{ VLbbn
this.sURL = sURL; A^\g]rmK
this.nStartPos = nStart; 60xL.Z
this.nEndPos = nEnd; Vf$$e)
nThreadID = id; '*G8;91u
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :=:m4UJb
} {=MRJg!U
jK{qw
Bf3 QB]9
public void run() =9:gW5F69
{ 7T(&DOGZ
while(nStartPos < nEndPos && !bStop) L=I;0Ip9y
{ /1xBZfrN
E!=Iz5
R I:kp.V
try{ nJwP|P_
URL url = new URL(sURL); _C,9c7K4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A,?6|g`q'
httpConnection.setRequestProperty("User-Agent","NetFox"); Ggbz
String sProperty = "bytes="+nStartPos+"-"; okO\A^F
httpConnection.setRequestProperty("RANGE",sProperty); ]\/"-Y#4Q
Utility.log(sProperty); 4K|O?MUNS
\GZ|fmYn
$3cZS
InputStream input = httpConnection.getInputStream(); 8zho\'
//logResponseHead(httpConnection); mp*?GeV?M
w8`B}Dr23
jcRe),
byte[] b = new byte[1024]; :OA;vp~$x
int nRead; G(bl)p^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FgMQ=O2
{ xZVZYvC,t
nStartPos += fileAccessI.write(b,0,nRead); 'oUTY *
//if(nThreadID == 1) Fx:4d$>;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <00=bZzX
} f @Vd'k<
2dDhO
WwxV}?Cf+
Utility.log("Thread " + nThreadID + " is over!"); @c).&7
bDownOver = true; UQbk%K2
//nPos = fileAccessI.write (b,0,nRead); x4v&%d=M
} lWUQkS
catch(Exception e){e.printStackTrace ();} |*l^<==
} ~m[Gp;pL
} 1yFIIj:^|
=o'g5Be<F
b)r;a5"<5
//打印回应的头信息 lWBewnLKE
public void logResponseHead(HttpURLConnection con) LyG`q3@
{ lcVG<*gf-
for(int i=1;;i++) C* 0ZF
{ }%D${.R]
String header=con.getHeaderFieldKey(i); G?Za/G
if(header!=null) w zi7pJjXh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PO,zP9
Utility.log(header+" : "+con.getHeaderField(header)); 3r[s_Y*
else Ve<f}
break; U(%6ny
} J'yCVb)V
} {~XAg~
VLoRS)
9~y:K$NO
public void splitterStop() >'jkL5l
{ 0IBQE
bStop = true; UUF]45t>
} SWyJ`
e7plL^^`
pwV~[+SS_
} =,X*40=
MooxT7
D$E#:[
/* hDc2T
**FileAccess.java 7\gu; [n
*//文件访问(定位，写) o'8%5M@
package NetFox; q(Ow:3&
import java.io.*; bH!_0+$P
^oNcZK>
j3u!lZ}U
public class FileAccessI implements Serializable{ *w/N>:V0p
N0N%~3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XD80]@\za
RandomAccessFile oSavedFile; 9Q\RCl_1
long nPos; F)@zo/u5L
;Eh"]V,e
VKg9^%#b`[
public FileAccessI() throws IOException kYR^
{ *^CN2tm
this("",0); fUPYCw6F
} c{qTVi5e
8<@X=Z
qxYCT$1
public FileAccessI(String sName,long nPos) throws IOException s4Vju/
{ ,fo7. h4{
oSavedFile = new RandomAccessFile(sName,"rw"); PF+Or
this.nPos = nPos; 7p>T6jK)
oSavedFile.seek(nPos); r>.l^U9hJ
} Qh*}v!3Jo
YdUcO.V
c5pK%I}O
public synchronized int write(byte[] b,int nStart,int nLen) 5'%O]~
{ J/PK#<
int n = -1; '{cFr
try{ 6rO^ p
oSavedFile.write(b,nStart,nLen); u`Kc\BSn
n = nLen; ft0tRv(s:
} 12Fnv/[n'K
catch(IOException e) 7uOtdH+
{ 6z'0fi|EN
e.printStackTrace (); 77j"zr7v
} C:f^&4 3
_,I~1"
LvU/,.$
return n; 3Q2NiYg3
} 5glEV`.je
ch0cFF^]
`S4G+j>u6
} 3K/]{ dkD
dP#7ev]'
gADqIPu]
/* fgHsg@33N
**SiteInfoBean.java =`Ky N/
*/ =FdFLrx~l
package NetFox; 17w{hK4o8O
/nEK|.j
UWdqcOr
public class SiteInfoBean { UF@.
, 10+Sh
m~&>+q ^7
private String sSiteURL; //Site's URL `M-
private String sFilePath; //Saved File's Path M. _5mZ{
private String sFileName; //Saved File's Name llCE}Vdh
private int nSplitter; //Count of Splited Downloading File (&, E}{p9
x}x)h3e
z`D|O|#q
public SiteInfoBean() _^!C4?2!
{//nSplitter的缺省值为5 $XKUw"%
//default value of nSplitter is 5 `V.tqZF
this("","","",5); `iEYq0}
} &v9"lR=_k
C;9P6^Oz
_T=";NSa
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `wSoa#U"@
{ r]kks_!Z
sSiteURL= sURL; .'2"83f
sFilePath = sPath; S'>KGdF
sFileName = sName; }"q#"s
this.nSplitter = nSpiltter; QX_![|=
A.YK=_J
b>d]= u
} Dhk$e
j-qg{oIJ
cvx"XxE,
public String getSSiteURL() ZT,auSX
{ PAVlZ}kj
return sSiteURL; +LF=oM<
} ]n$ v ^
5cl^:Ua
V=+p8nE0
public void setSSiteURL(String value) TaKCN
{ "`'+@KlE
sSiteURL = value; ur]WNk8bN
} UY:Be8C A
WJ 'lYl0+7
]]5(:>l
public String getSFilePath() F'_z$,X6
{ .li)k[] ts
return sFilePath; DvA#zX[
} P#;pQC
kjSzuqB
mmMiA@0
public void setSFilePath(String value) =sS=
{ IEfm>N-]
sFilePath = value; GW]t~EL
} 6S(`Bw8h
5Iv"
]0{,P !
public String getSFileName() =E~_F>SD
{ *6v5JH&K
return sFileName; cc"<H}g>`
} nYj7r*e[
q"-Vh,8h
~fO#En
public void setSFileName(String value) d 5hx%M
{ ~{6}SXp4U
sFileName = value; XU}" h&>
} T8j<\0WW
V7+/|P_
^q<EnsY
public int getNSplitter() s2nZW pIy
{ eE{ 2{C
return nSplitter; Y2+YmP*z`
} va.Ve# N
)P.,h&h/
[c99m:*+
public void setNSplitter(int nCount) sr:hRQ27
{ \ow(4O#
nSplitter = nCount; q?f-h<yRQ
} -BsZw. 7P
} Mv7tK l
~"h V-3U
O:dUzZR['
/* 7[}WvfN8#
**Utility.java zaE!=-U
*/ *mN8Qd
package NetFox; ;47=x1ji
"&mwrjn"T
HZ\=NDz
public class Utility { <(us(zbk]
\/r]Ra
=e6!U5 f
public Utility() A}1:fw\Fn3
{ #|Je%t}~
`oE.$~'
fl*49-d
} Ba n^wX
=1mIk0H`
//线程睡眠 3LVL5y7|
public static void sleep(int nSecond) &2W`dEv]?
{ }BCxAwD4
try{ n$"BF\eM
Thread.sleep(nSecond); !,*Uvs@b
} 2}ywNVS
catch(Exception e) L_>LxF43
{ McvLU+
e.printStackTrace (); iyMoLZ5
} ;i3C
} 1oG'm
*(VwD)*
//日志 V_)465g
public static void log(String sMsg) xf{=~j/L
{ 4{" v
System.err.println(sMsg); C7Hgzc|U
} "l6Ob
COSQ
Z0Qh7xWve
public static void log(int sMsg) q4u-mM7#7
{ _6yrd.H
System.err.println(sMsg); ~@iYP/=/Q
} 1,6Y)_
} ?/KkN3Y_j[
H"|oI|~
;{g>Z|
/* rrZ'Dz
**TestMethod.java 8p~|i97W]!
*/ By0Zz
package NetFox; $tebNiP
v1E(K09h2
JRw)~Tg @
public class TestMethod { zZ])G
46c0;E\9
?qtL*;
public TestMethod() BCr*GtR)W
{ ///xx/weblogic60b2_win.exe 5OC3:%g
try{ SJ:Wr{ Or3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); mmEe@-lE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~G~:R
SiteFileFetch fileFetch = new SiteFileFetch(bean); L4Si0 K
fileFetch.start(); |C\XU5}
} QWK\6
catch(Exception e){e.printStackTrace ();} Dn;$4Dak(
y Xi$w.gr
6;}FZ
} U6_GEBz~y
kn6X I*
<t. w(?
public static void main(String[] args) RSf*[2
{ l' a<k"
new TestMethod(); F#7A6|
} IQ9Rvnna
} ==~ lc;
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