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)); S"V|BU
} JM@MNS_||(
for(int i=0;i<nEndPos.length-1;i++) mQ:lj$Gf
{ j8_WEjG
nEndPos = nStartPos[i+1]; U2\zl
} ['e8Xz0
nEndPos[nEndPos.length-1] = nFileLength; e%u1O-*
} 9!}&&]Q`
} >Y!5c 2~`;
mO(m%3
-}4<P}.5T
//启动子线程 K9:I8E<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hZU@35~BN
for(int i=0;i<nStartPos.length;i++) =T|Z[/fto
{ H<Ed"-n$I<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rq:R6e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /2tgxm$}
nStartPos,nEndPos,i); Xq` '^)
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cEhwv0f!qS
fileSplitterFetch.start(); 2a3i]e5Kt
} s:~3|D][
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #0zMPh /U}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ej4xW~_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3T+#d-\
nEndPos = " + nFileLength); /:~mRf^
// fileSplitterFetch[nPos.length-1].start(); _r^Cu.[7
YP5V~-O/
.r[kNh@ b%
//等待子线程结束 8fY1~\G:\
//int count = 0; [f!sBJ!
//是否结束while循环 OjcxD5"v9
boolean breakWhile = false; =I-SQI8
tl !o;`W
y_;LTCj?
while(!bStop) _ )b:F=4j
{ 4en[!*
write_nPos(); ]hJ#%1
Utility.sleep(500); NnRR"'
breakWhile = true; )`, Bt
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+vY8HQ|v
for(int i=0;i<nStartPos.length;i++) tg_v\n
{ R/VrBiw
if(!fileSplitterFetch.bDownOver) TyI"fP
{ }'U"HHv
breakWhile = false; /J")S?. [u
break; WPPz/c|j
} 7j8nDX<
} }\!&3^I
if(breakWhile) $<xa "aN!
break; vc0'x4
-]C3_ve
-|"W|K?nq
//count++; &-mPj82R
//if(count>4) mI_ ?hl?Pv
// siteStop(); iaPrkMhd
} wi-O}*O
zUF%`CR
7A@]t_83Y
System.err.println("文件下载结束！"); qq9fZZb
} @*`9!K%
catch(Exception e){e.printStackTrace ();} =87.6Ai
} -rb]<FrL^
BG\g`NK}Z
y9kydu#q
//获得文件长度 ?nZQTO7
public long getFileSize() I<PKwT/?
{ -HutEbkjx
int nFileLength = -1; p~1!O]qLt
try{ +KGZk?%
URL url = new URL(siteInfoBean.getSSiteURL()); #+I)<a7\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]k &Y )
httpConnection.setRequestProperty("User-Agent","NetFox"); "ph&hd}S
5v<X-8"
+n_`*@SE
int responseCode=httpConnection.getResponseCode(); {ULyB$\-
if(responseCode>=400) )`<- c2
{ )L fXb9}
processErrorCode(responseCode); %%5K%z,R#
return -2; //-2 represent access is error 6EfGJq
} yU`"]6(@[
zX*+J"x
MLf,5f;e
String sHeader; f4eLnY
gBBS}HF
cyu)YxT
for(int i=1;;i++) Z:7X=t=
{ tu{y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yyCx;
//Utility.log(in.readLine()); $Pv;>fHu
sHeader=httpConnection.getHeaderFieldKey(i); m/vwM"
if(sHeader!=null) wju2xM
{ $n>|9(K8
if(sHeader.equals("Content-Length")) ?|Y/&/;%I
{ o0t/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C QO gR GW
break; YbjeM6#E
} BIyNiol$AJ
} S^ij%
else ZtG5vdf
break; =gL~E9\
} fS2 ^$"B|
} k=L(C^VP
catch(IOException e){e.printStackTrace ();} :y#KR\T1
catch(Exception e){e.printStackTrace ();} <7Igd6u
rBG8.E36J
"uK`!{
Utility.log(nFileLength); AWSe!\b
E{_$C!.
wa/ :JE
return nFileLength; 3%c{eZxG=
} 9nIBs{`/Ac
lB_&Lq8G
@w:6m&KL9
//保存下载信息（文件指针位置） NgH"jg-
private void write_nPos() eF)vx{s
{ DSiI%_[Ud
try{ e+J|se4L5
output = new DataOutputStream(new FileOutputStream(tmpFile)); p<hV7x-{
output.writeInt(nStartPos.length); 'U=D6X%V9m
for(int i=0;i<nStartPos.length;i++) A'(v]w
{ {p#[.E8
// output.writeLong(nPos); Okd?=*sBx
output.writeLong(fileSplitterFetch.nStartPos); -UgD
output.writeLong(fileSplitterFetch.nEndPos); pi`sx[T@{Z
} =+@IpXj
output.close(); 5\1C@d
} B1\@ n$
catch(IOException e){e.printStackTrace ();} W '54g$T
catch(Exception e){e.printStackTrace ();} 2x3'm
} CYlZ<W'
GMLDmTV
Mx& P^#B3
//读取保存的下载信息（文件指针位置） -8F~Tffx
private void read_nPos() }*0OLUFFJ
{ L_$M9G|5n
try{ sA6Ku(9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \g|u|Y.2[
int nCount = input.readInt(); ;-Bi~XD
nStartPos = new long[nCount]; 9D 2B8t"a
nEndPos = new long[nCount]; %\xwu(|kN
for(int i=0;i<nStartPos.length;i++) !L5[s
{ ("HT0&#a
nStartPos = input.readLong(); 4.@gV/U(|
nEndPos = input.readLong(); I^'U_"vB
} n|,kL!++.
input.close(); cZnB 2T?
} =l&A9 >\
catch(IOException e){e.printStackTrace ();} $O|J8;"v
catch(Exception e){e.printStackTrace ();} Rxe sK
} F,B,D^WD
S(;3gQ77
/*B^@G|]'
private void processErrorCode(int nErrorCode) j\t"4=,n
{ Mk-C&#'
System.err.println("Error Code : " + nErrorCode); "+^d.13+]
} JvFU7`4@
dL9QYIfP
4BSSJ@z
//停止文件下载 wr\d5j
public void siteStop() Z$h39hm?c
{ K<`"Sr
bStop = true; |Tz/9t
for(int i=0;i<nStartPos.length;i++) FBfyW- 7
fileSplitterFetch.splitterStop(); (+g!~MP
+*OY%;dQ7@
7.O1 ~-
} qGS]2KY
} ti`R
//负责部分文件的抓取 (^h47kY
**FileSplitterFetch.java y@!kp*0
*/ 0q_Ol]<V
package NetFox; zw=as9z1-
#^IEQZgH
9HI9([Cs
import java.io.*; 8YI.f
import java.net.*; ^FLuhLS\*
7 R1;'/;
8.vPh
public class FileSplitterFetch extends Thread { GvQ|+vC
5S:&^ A<
.MO"8}]8Z
String sURL; //File URL |0Kj0u8T
long nStartPos; //File Snippet Start Position Q!DQ!;Br6
long nEndPos; //File Snippet End Position TI-#\v9
int nThreadID; //Thread's ID -B\`O*Q
boolean bDownOver = false; //Downing is over 2fc8w3
boolean bStop = false; //Stop identical 22?9KZ`Z=
FileAccessI fileAccessI = null; //File Access interface 7S<Z&1(
?3tR(H<
MmOGt!}9A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException !Xt=+aKN
{ >c~~i-=
this.sURL = sURL; =U3,P%
this.nStartPos = nStart; %v++AcE
this.nEndPos = nEnd; xBGSj[1`i
nThreadID = id; fT.5@RR7^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9.5hQZ
} Hl&]r'bK
>iP>v`J
cm]D"GFLY
public void run() l7 D/]&
{ ;FYiXK%
while(nStartPos < nEndPos && !bStop) ilv6A9/
{ Vxif0Bx&/d
&o/&T{t}
:xd&V%u`
try{ F]Zg9c{#
URL url = new URL(sURL); !ViHC}:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DvnK_Q!
httpConnection.setRequestProperty("User-Agent","NetFox"); BY: cSqAW
String sProperty = "bytes="+nStartPos+"-"; whP>'9t.w
httpConnection.setRequestProperty("RANGE",sProperty); (E)/' sEb
Utility.log(sProperty); %j=E}J<H5*
cXcn}gKV
8}p5MG
InputStream input = httpConnection.getInputStream(); >*A\/Da]j
//logResponseHead(httpConnection); La}=Ng
9;;1 "^4/
g#=^U`y
byte[] b = new byte[1024]; R{.wAH(
int nRead; Ki-CJy
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z$p+l]
{ $Vp&Vc8
nStartPos += fileAccessI.write(b,0,nRead); r2QC$V:0
//if(nThreadID == 1) <u44YvLBm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $i@5'[jA
} F!{N4X>%T
*n?6x!A
'dj}- Rs
Utility.log("Thread " + nThreadID + " is over!"); T$%u=$E%F
bDownOver = true; 6" 3!9JC
//nPos = fileAccessI.write (b,0,nRead); I_xJ[ALdm
} B!<{s'
catch(Exception e){e.printStackTrace ();} -'k<2"z
} nngL,-v#F
} s@o"V >t
%{/0K<M
Uy ;oJY
//打印回应的头信息 I}Q3B3Byg
public void logResponseHead(HttpURLConnection con) Fg4eIE-/M
{ wr*A%:
for(int i=1;;i++) pM[UC{
{ [sz#*IJ
String header=con.getHeaderFieldKey(i); OR&+`P"-\
if(header!=null) wlKpHd*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @tjC{?5Y
Utility.log(header+" : "+con.getHeaderField(header)); \{?v|%n=/i
else LEVNywk[
break; wb4 4
} ZH:#~Zyj
} 21cB_"
z!Jce}mx
KUH&_yCRB
public void splitterStop() +cy(}Vp
{ h.'h L
bStop = true; xKsn);].`
} X?rJO~5
9>@_};l
lW&glU(
} pfAp2"
TaM,9MAu
]RnX'yw^
/* */\dH<
**FileAccess.java RWA|%/L
*//文件访问(定位，写) {LJCY<IGq
package NetFox; &;9<a^td
import java.io.*; /q='~t
=]W{u`
5bmtUIj
public class FileAccessI implements Serializable{ )IZ$R*Y{
@ n;WVG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~n"V0!:'4
RandomAccessFile oSavedFile; a3Es7R+S
long nPos; $ Qg81mu
mq'q@@:c
HdWghxz?)
public FileAccessI() throws IOException =#%e'\)a
{ aKCCFHq t!
this("",0); WlZ[9,:p1
} Q1eiU Y6
|7%$+g
Y!&dj95y
public FileAccessI(String sName,long nPos) throws IOException >47,Hq:2
{ uX}M0W
oSavedFile = new RandomAccessFile(sName,"rw"); x6Z$lhZ
this.nPos = nPos; %q>gwq A
oSavedFile.seek(nPos); kV6>O C&^
} wK#UFOp
5W<BEcV\
zKV{JUpG
public synchronized int write(byte[] b,int nStart,int nLen) =t)eT0
{ 5Y9 j/wA
int n = -1; !2&h=;i~V
try{ )J#@L*
oSavedFile.write(b,nStart,nLen); 62vz 'b
n = nLen; JI\u -+BE
} vgE5(fJh
catch(IOException e) _\o +9X!
{ @Gn9x(?J
e.printStackTrace (); 9MM4C
} yMz@-B
}3[ [ONA
G2L7_?/m
return n; a.8nWs^
} cW&OVNj
Za}91z"
TS3 00F
} k,v.U8
l^0 <a<P
:syR4A WM
/* \D}/tz5~B
**SiteInfoBean.java c1n? @L
*/ &]z2=\^e
package NetFox; |u;5|i
V<nzThM\
Zqam Iq
public class SiteInfoBean { 9pjk3a
R~Xl(O
/Zv}u
private String sSiteURL; //Site's URL VCc4nn#
private String sFilePath; //Saved File's Path U}Hmzb
private String sFileName; //Saved File's Name 5jjJQ'
private int nSplitter; //Count of Splited Downloading File 7?hCt
SH}O?d\Q:
Y}f%/vus
public SiteInfoBean() U_I'Nz!^t
{//nSplitter的缺省值为5 = )(;
//default value of nSplitter is 5 L YH9P-5H
this("","","",5); >J8?n,*
} tU)+q?Mw
{n1o)MZ]R
'mmyzsQ\6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o-)E_X
{ iSFgFJG^
sSiteURL= sURL; r2&{R!Fj`
sFilePath = sPath; 3{$cb"5
sFileName = sName; `pcjOM8u
this.nSplitter = nSpiltter; 6(ja5)sn*
X)uT-Fy
J-,T^Wv
} bq ~'jg^#
l_}c[bAUu
c8}1-MKs_R
public String getSSiteURL() vk#xCggK
{ _wHqfj)
return sSiteURL; 7CQ48LH]
} jliKMd<?
Tp0Tce/
92} ,A`=
public void setSSiteURL(String value) ZGp8$Y>r
{ Y+G4:
sSiteURL = value; ul% q6=f)
} TkQ05'Qc
3cOXtDV YT
m$O@+;>l
public String getSFilePath() .+M4Pi
{ }QC:!e,yG
return sFilePath; /Hd\VI
} O~xc> w
;CU3CLn
="I]D I
public void setSFilePath(String value) Pp.X Du
{ HWs?,AJNxB
sFilePath = value; (,<?Pg7v:f
} 8}S|iM
x&?35B i
Ii,L6c
public String getSFileName() ZsV'-gu
{ *~-~kv4-
return sFileName; E&"bgwav{(
} xwz2N5
&t6L8[#yd
^,`yt^^A
public void setSFileName(String value) I=lA7}
{ *J%+zH
sFileName = value; [(dAv7YbN
} .UJDn^@
|:EUh
2=U4'C4#
public int getNSplitter() L;v#9^Fq
{ sa*hoL18
return nSplitter; 9vVYZ}HC
} z1YC%Y|R
8cW]jm
&d~6MSk
public void setNSplitter(int nCount) @s@r5uR9B
{ UHxXa*HyI
nSplitter = nCount; GadD*psD2
} oFY'Ek;d
} 0gnr@9,X
?N`W,
]i{-@Ven
/* [zY9"B<3
**Utility.java (s\Nm_j
*/ 3 i>uKU1
package NetFox; LdRLKE<'e
="XxS|Mq3
Q+#, VuM
public class Utility { G:A` n;E0
uS<&$JH
iXXgPapz
public Utility() PY) 74sa
{ .+ _x|?'
xe_c`%_
%)]{*#N4
} 7MBz&wE^f
n.Ekpq\
//线程睡眠 ,@GI3bl
public static void sleep(int nSecond) `A?/Ww>;
{ Plt~l3_
try{ SVeL c
Thread.sleep(nSecond); zvSfW# *
} 6LUB3;g7
catch(Exception e) ;[%AeN5W
{ E?%rmdyhL!
e.printStackTrace (); mGoUF$9 k
} c!6.D
} HbV[L)zYG
k}JjSt1_A;
//日志 B(E+2;!QF
public static void log(String sMsg) DQwbr\xy\
{ Xo$(zGb
System.err.println(sMsg); ^F_c'
} 7eZ,; x
+jQW6k#
.p <!2
public static void log(int sMsg) @0+@.&Z
{ 3M/kfy
System.err.println(sMsg); i]YH"t8GY
} -R|v&h%T
} !.kj-==s{7
_PQQ&e)E
"y#$| TMB
/* l8jm7@.E
**TestMethod.java JrS|Ib)6
*/ 4fQ<A <2/
package NetFox; `Y8F}%i[
q,kdr)-
/2WGo-
public class TestMethod { | [P!9e
C+jlIT+
{ge^&l
public TestMethod() O &;Cca
{ ///xx/weblogic60b2_win.exe Un@dWf6'
try{ A"d=,?yE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T[q2quXgk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qN[U|3k
SiteFileFetch fileFetch = new SiteFileFetch(bean); 08cCrG
fileFetch.start(); qy/xJ>:
} f D2.Zh
catch(Exception e){e.printStackTrace ();} eUQrn>`
x7>' 1
2I>X]r.S!1
} MBp%TX!
}~y i6!w'
N-y[2]J90
public static void main(String[] args) "V}WV!w
{ |!,;IoZ
new TestMethod(); 1F{c5
} SwXVa/9a"
} <D%.'=%pZ
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