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)); @MS}tZ5
} _%xe:X+ M
for(int i=0;i<nEndPos.length-1;i++) 9\_^"5l
{ g/o@,_
nEndPos = nStartPos[i+1]; B~[QmK
} w&vZ$n-|
nEndPos[nEndPos.length-1] = nFileLength; xH\#:DLY
} [IF5Iv\b
} ,:I:F
F ka^0
3N(5V;ti
//启动子线程 <}G*/ z?/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i;u#<y{E
for(int i=0;i<nStartPos.length;i++) ~]MACG:'
{ Ej\Me
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \F$Vm'f_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9vQI ~rz?
nStartPos,nEndPos,i); LFzL{rny!U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x6i7x"
fileSplitterFetch.start(); #%~PNki
} DLigpid
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @O!BQ^'hk#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |XDbf3^6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +b =X~>vZ
nEndPos = " + nFileLength); Hwz.5hV"
// fileSplitterFetch[nPos.length-1].start(); u<VR;p:y
4"om;+\
f,jN"
//等待子线程结束 +N|}6e
//int count = 0; p;y\%i_
//是否结束while循环 :i?7RouO
boolean breakWhile = false; ~`xaBz0q
,2|(UTv
MO_-7,.y
while(!bStop) c#ahFpsnlw
{ 'n>v}__&|
write_nPos(); ,ln=kj
Utility.sleep(500); ]4uY<9VL
breakWhile = true; 8|z@"b l)
g< F7UA
^$N}[1
for(int i=0;i<nStartPos.length;i++) 0r=KY@D
{ pie,^-_.g
if(!fileSplitterFetch.bDownOver) CeZ+!-lG
{ ujLz<5gKuO
breakWhile = false; A-&'/IHR"B
break; (GeOD V?U
} \l_U+d,qq
} qg`8f?
if(breakWhile) W$>AK_Y}
break; F['<;}
?oD]J
&OMe'P
//count++; $:RP tG
//if(count>4) <Z>p1S
// siteStop(); -p-<mC@<&S
} "PK`Ca@`v
[X\<C '<
URo#0fV4C
System.err.println("文件下载结束！"); :L6,=#
} IyV%tOy
catch(Exception e){e.printStackTrace ();} k"L?("~
} !eC]=PoY
xoYaL
)LdS1%
//获得文件长度 q83!PI
public long getFileSize() ] 'B4O1
{ 0dKv%X#\
int nFileLength = -1; \7d T]VV
try{ C)RJjaOr
URL url = new URL(siteInfoBean.getSSiteURL()); U9/>}Ni%3G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {ch+G~oS
httpConnection.setRequestProperty("User-Agent","NetFox"); B.oD9<9
Q+ogVvMq>
%n!7'XF'[
int responseCode=httpConnection.getResponseCode(); 6a%dq"5 +
if(responseCode>=400) S#|dmg;p
{ yQ/E0>Uj!
processErrorCode(responseCode); ;+Mee^E>!
return -2; //-2 represent access is error dBG5IOD
} KB\A<(o,
F5(DA
}R\;htmc;
String sHeader; <`P7^ 'z!
'k1vV
m+LP5S
for(int i=1;;i++) C"[d bh!
{ p4sU:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZR|n\.
//Utility.log(in.readLine()); :%2uZ/cG(
sHeader=httpConnection.getHeaderFieldKey(i); 'X(Sn3
if(sHeader!=null) 4^uwZ:
{ `}o{o
if(sHeader.equals("Content-Length")) |jw{7\+
{ i[r>^U8O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6EY W:o
break; |k[hk
} 0\DlzIO
} 8HxtmFqG
else ^a#
break; BqG7Et
} U+7!Vpq
} Cz)/Bq
catch(IOException e){e.printStackTrace ();} FS^ie|8{D-
catch(Exception e){e.printStackTrace ();} KpF/g[m
5y8ajae:
^>/] Qi
Utility.log(nFileLength); /~6)Vt
FXO{i:Zo
nR#'BBlI
return nFileLength; y-R:-K XH=
} i0py5Q
vIpitbFC
"IMq +
//保存下载信息（文件指针位置） vWq/A.
private void write_nPos() ^oH!FN`;{
{ D]B;5f
try{ ~X2 cTG!,
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^QbaMX
output.writeInt(nStartPos.length); je`w$ ^w
for(int i=0;i<nStartPos.length;i++) F0 ^kUyF|
{ v#ERXIrf
// output.writeLong(nPos); 0?/vcsO
output.writeLong(fileSplitterFetch.nStartPos); ("T8mt[w>
output.writeLong(fileSplitterFetch.nEndPos); 6SVh6o@]
} iD`>Bt7gD
output.close(); &8'QD~
} ^,,lo<d_L
catch(IOException e){e.printStackTrace ();} eczS(KoL4
catch(Exception e){e.printStackTrace ();} -gR }^D
} MB3 0.V/\
,`.`}'
b_%W*Q
//读取保存的下载信息（文件指针位置） \L4+Dv<z
private void read_nPos() <h[l)-86
{ A;e0h)F$-
try{ \h UE,^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $,DX^I%!
int nCount = input.readInt(); ~h@<14c{X
nStartPos = new long[nCount]; f3M~2jbv'p
nEndPos = new long[nCount]; ` 8OA:4).
for(int i=0;i<nStartPos.length;i++) O}cg1Q8p
{ xjO((JC
nStartPos = input.readLong(); O({vHqN>
nEndPos = input.readLong(); l!9G
} WlfS|/\%V^
input.close(); BBUXoz
} 97~*Z|#<+
catch(IOException e){e.printStackTrace ();} Ii4lwZnz
catch(Exception e){e.printStackTrace ();} dX>l"))yR
} +pMjm&CF
Bvy(vc=UDW
"J(7fL$!
private void processErrorCode(int nErrorCode) f7Fr%*cO
{ 2O~I.(9(
System.err.println("Error Code : " + nErrorCode); \/ 8 V|E
} "Ca?liy
_O*"_^6
Tr@}
//停止文件下载 K;}h u(*\]
public void siteStop() <^,5z!z}
{ k2S6 SB
bStop = true; ?[K\X
for(int i=0;i<nStartPos.length;i++) WF{rrU:
fileSplitterFetch.splitterStop(); L8zY?v(bG
3#@ETt0X(
(!0=~x|Z[
} WV'FW)%
} Wi?37EHr
//负责部分文件的抓取 '[h|f
**FileSplitterFetch.java Jc:gNQCsP
*/ 2nFSu9}+r
package NetFox; 9rn[46s`
JRC+>'}Xj
!PzlrH)M=p
import java.io.*; aiKZ$KLC
import java.net.*; M)U 32gI:
G^]7!:0
4oF8F)ASj
public class FileSplitterFetch extends Thread { 1o;+.]B
P"<HxT?
Ba\l`$%X
String sURL; //File URL [Pu~kiN
long nStartPos; //File Snippet Start Position }lk_Oe1
long nEndPos; //File Snippet End Position /Wh} ;YTv^
int nThreadID; //Thread's ID ^]$x/1I;
boolean bDownOver = false; //Downing is over Q`Q%;%t
boolean bStop = false; //Stop identical FX FTf2*T
FileAccessI fileAccessI = null; //File Access interface 5Z7<X2
wPn#>\/L
;^Vsd\ac0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 24)3^1P\V
{ ?dukK3u
this.sURL = sURL; @}K'Ic
this.nStartPos = nStart; -|MeC
this.nEndPos = nEnd; n+M:0{Y|
nThreadID = id; 8xQ5[Ov
fileAccessI = new FileAccessI(sName,nStartPos);//定位 vMiZ:*iaj@
} g3%Xh0007{
!79^M
,OX(z=i_
public void run() IRemF@
{ ZkW,
while(nStartPos < nEndPos && !bStop) S;[*5g6a&x
{ :!M/9D*}0
-bo5/`x
1Z?en
try{ vr|9NP]v
URL url = new URL(sURL); Tw< N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6uCa iPV
httpConnection.setRequestProperty("User-Agent","NetFox"); ,%#FK|
String sProperty = "bytes="+nStartPos+"-"; 9pKN^FX,76
httpConnection.setRequestProperty("RANGE",sProperty); J~6+zBF
Utility.log(sProperty); fPf8hz>
)z/+!y
,BCtNt(
InputStream input = httpConnection.getInputStream(); TC80nP
//logResponseHead(httpConnection); >;eWgQ6V
l+'@y (}Q
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byte[] b = new byte[1024]; XYtDovbv&
int nRead; $DZ\61
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [];*9vxW
{ QAigbSn]
nStartPos += fileAccessI.write(b,0,nRead); #Jv|zf5Z
//if(nThreadID == 1) :b[ [}'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _-$"F>
} MzRwsf
LfEeFF=#n
P08=?
Utility.log("Thread " + nThreadID + " is over!"); 4k5X'&Q
bDownOver = true; 'c3P3`o,;
//nPos = fileAccessI.write (b,0,nRead); CfKvC
} *2ZX*w37
catch(Exception e){e.printStackTrace ();} Hn5:*;N
} >M{=qs
} n`Pwo&
nqNL[w6{
M=$ qus
//打印回应的头信息 o(GXv3L
public void logResponseHead(HttpURLConnection con) f]MKNX
{ 1'or[Os3=
for(int i=1;;i++) QH:k5V~
{ 8"L#5MO t
String header=con.getHeaderFieldKey(i); BbEWa
if(header!=null) q(sEN!^L`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1zwk0={x-%
Utility.log(header+" : "+con.getHeaderField(header)); Gf'qPLK0
else hh/C{ l
break; 'NyIy:
} | +osEHC
} `)Z"||8K
ocCq$%Ka
ME"B1Se\
public void splitterStop() U.]5UP:a
{ #=mLQSiQ
bStop = true; K.s\xA5`_
} u~WBu|
Y 3W_Z
5VD(fW[OW]
} iV#sMJN9
jFbj)!;
<d89eV+
/* Fk(nf9M%
**FileAccess.java Y+vG]?D
*//文件访问(定位，写) t5: 1' N9P
package NetFox; B:Y"X:Y
import java.io.*; KE>|,Ur
jeb]3i=pw
Jbv66)0M
public class FileAccessI implements Serializable{ &QHZ]2%U
D d['e
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (QS4<J"
RandomAccessFile oSavedFile; ^pgVU&-~]/
long nPos; KrVP#|9%"
=.T50~+M
ykAZP[^'
public FileAccessI() throws IOException RuyqB>[o
{ %gBulvg
this("",0); 2F5*C
} dsJMhB_41U
>3aB{[[N
1ym^G0"s
public FileAccessI(String sName,long nPos) throws IOException 7]\_7L|>]
{ Xy(8}
oSavedFile = new RandomAccessFile(sName,"rw"); 3|++2Z{},
this.nPos = nPos; KZeaM
oSavedFile.seek(nPos); vs=8x\W
} iO$Z?Dyg9
|q+3X)Y
h"#[{$(
public synchronized int write(byte[] b,int nStart,int nLen) ^@91BY
{ "~V|p3
int n = -1; <!qN<#$y
try{ 2!@ER i
oSavedFile.write(b,nStart,nLen); hCpX#rg?
n = nLen; !H)Cua)
} AFMIp^F
catch(IOException e) oItEGJ|
{ C!,|Wi2&
e.printStackTrace (); qoZUX3{
} FaA'%P@
\d:AV(u
]h3{MTr/
return n; cc0e(\
} GkU]>8E'"
"pA24Ze
TyGsSc
} v% c-El%
qI=j>x
V;N'?Gu
/* F/ si =%
**SiteInfoBean.java tNbL)
*/ T[(4z@d`5
package NetFox; ;NoD4*
!C6[m1F
W)LtnD2 w
public class SiteInfoBean { sUe<21:
RCC~#bb
zZE@:P&lf
private String sSiteURL; //Site's URL w~a_FGYX
private String sFilePath; //Saved File's Path EJByYk
private String sFileName; //Saved File's Name ^2f2g>9j_C
private int nSplitter; //Count of Splited Downloading File nqv#?>Z^OT
.9uw@Eq
Yn>y1~
public SiteInfoBean() Y I?4e7Z+
{//nSplitter的缺省值为5 SbYsa
//default value of nSplitter is 5 -]Mbe2;
this("","","",5); u27*-X 5
} _mG>^QI.
6 _n~E e
&Jf67\N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -. J@
{ ?ISv|QpC
sSiteURL= sURL; 6Gj69Lr
sFilePath = sPath; ^v+7IFn
sFileName = sName; &60#y4
this.nSplitter = nSpiltter; O_^X:0}
>XU93 )CX
^2<nn op
} dk@j!-q^
g@s'-8}X^
{!av3Pz\
public String getSSiteURL() ) mG
{ @7z_f!'u
return sSiteURL; :/6gGU>pu
} k<.VR"I p
*#&s+h,^
Z.{r%W{2
public void setSSiteURL(String value) R2B0?fu
{ 2nv-/%]
sSiteURL = value; _VFL}<i
} D Kng.P
5Vu@gRk_
-)o0P\cTEt
public String getSFilePath() #fkOm Y7X
{ k_A 9gj1
return sFilePath; kFZjMchm A
} 8pE0ANbq
5;yVA
*p>1s!i
public void setSFilePath(String value) [*2|#KSCX
{ qE)G;Y<,1
sFilePath = value; "PtOe[Xk
} f^D4aEU
6H:'_|G
?D]qw4J
public String getSFileName() EC0M0qQ
{ _>)=c<HL
return sFileName; eK_Yt~dj
} [-*8S1
OK1f Y`$z
/`YbHYNF[
public void setSFileName(String value) Z+J;nl
{ U<Z\jT[
sFileName = value; |&xjuBC
} 1WbawiG}
u9~RD
q oJ4w7
public int getNSplitter() YkqauyV^
{ M!E#T-)
return nSplitter; /naGn@m5u
} 4t;m^Iv
J&jNONu?
!YJ^BI
public void setNSplitter(int nCount) gbc])`aJ>
{ TR([u
nSplitter = nCount; i<%
} }^/;8cfLY
} .7EZB
<78LB/:
7h3JH
/* bAl0z)p
**Utility.java 3ZKaqwK
*/ 68v59)0U
package NetFox; }{(|^s=
9&t!U+
hm5A@Z
public class Utility { UIl^s8/
8*V8B=q}K
>5|;8v-r
public Utility() VSI.c`=,
{ M+N7JpR
$CYB&|d
)5M9Ro7
} U2(|/M+
jt/ |u=
//线程睡眠 T'TxC)
public static void sleep(int nSecond) J&IFn/JK$
{ QhHexr6
try{ cKj6tT"=O
Thread.sleep(nSecond); fWBI}~e
} A-dL_3
catch(Exception e) &xwAE*}
{ cP~?Iz8nD
e.printStackTrace (); Cl+TjmOV\`
} ]GS@ub
} $K,6!FyBa
FrNW@
//日志 Kb#}f/
public static void log(String sMsg) ]v^;]0vcr
{ W,^(FR.
System.err.println(sMsg); Va1 eG]jQ
} EPz$`#Sh"
Czs4jHTa`
lj1wTiaI(
public static void log(int sMsg) +c699j;[
{ |x AwiF_
System.err.println(sMsg); E!4Qc+.
} g]g2`ab |
} \sIRV}Tk}N
V^t5 Y+7
jaAv_=93f
/* jG3}V3|.
**TestMethod.java 2wWL]`(E
*/ G~{xTpL
package NetFox; I [J0r
`O5kI#m)L*
}[u9vZL
public class TestMethod { |f^/((:D
0 mWfR8h0
m<BL/7
public TestMethod() #lax0IYY=
{ ///xx/weblogic60b2_win.exe >8V;:(nt
try{ W?"Z>tgp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FxKb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?wps_XU
SiteFileFetch fileFetch = new SiteFileFetch(bean); E\r5!45r
fileFetch.start(); *|x2"?d-F:
} 'nNw
catch(Exception e){e.printStackTrace ();} |67j__XC
*n0k2 p
eBTy!!
} UcMe("U
-/aDq?<<
VwoCRq*
public static void main(String[] args) 5FHpJlFK,
{ _[V.%k
new TestMethod(); 0>-l {4srs
} &b}!KD1
} b9(d@2MtK
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