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)); $/pd[H[{
} lYJ]W[!
for(int i=0;i<nEndPos.length-1;i++) fQe-v_K
{ <M 7WWtmx
nEndPos = nStartPos[i+1]; ?= ulfGrY
} R%5\1!Fl=G
nEndPos[nEndPos.length-1] = nFileLength; ';$2j~
} vB#3jI
} FTk!Mn88
&&>OhH`
.@xwl}o$OL
//启动子线程 Z!hDTT
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;AHa|35\
for(int i=0;i<nStartPos.length;i++) H!s &]b
{ 1Z*-@%RX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZT|E1[Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~+4OG 0
nStartPos,nEndPos,i); r5rK>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bup;4~g
fileSplitterFetch.start(); Ig S.U
} O":x$>'t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /Nxy?g|,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sV{[~U,|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !d"J,.)
nEndPos = " + nFileLength); 9ft7
// fileSplitterFetch[nPos.length-1].start(); ,.F,]m=
uTn(fs)D
<0Q`:'\.>
//等待子线程结束 pU}>}
//int count = 0; 7@C:4c@0
//是否结束while循环 V!~uGf
boolean breakWhile = false; 8$@gAlI^
jaNkWTm:
)Ax1?Nx$
while(!bStop) 6Zkus20
{ C2!POf;GdN
write_nPos(); x?f3XEA_
Utility.sleep(500); h-#Glse<
breakWhile = true; bJGT^N@
w^P4_Yr[T
8l)^#"ySA
for(int i=0;i<nStartPos.length;i++) W;u~}k<
{ GHH1jJ_[7
if(!fileSplitterFetch.bDownOver) 5\qoZs*e
{ : h-N
breakWhile = false; du`],/ 6
break; ,mjwQ6:Ny
} whxE[Xnv
} z<s]Z
if(breakWhile) iB[%5i-
break; \6nWt6M
=>/aM7]
!QP~#a%
//count++; 2hu;N
//if(count>4) zFwp$K>{QY
// siteStop(); 2&06Db(
} D4;V8(w=#
0xZq?9a
m {wMzsQ
System.err.println("文件下载结束！"); >qCUs3}C{*
} ZZ?=^g
catch(Exception e){e.printStackTrace ();} )2u=U9
} c7P"1
Hg]Q.SeJ(
+7d%)t
//获得文件长度 u;;]S!:M
public long getFileSize() j$Gb>Ex>
{ @yS
int nFileLength = -1; rhwY5FD?
try{ -=O9D-x=
URL url = new URL(siteInfoBean.getSSiteURL()); )O2giVq7[0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A)s
httpConnection.setRequestProperty("User-Agent","NetFox"); B,,f$h!
h#'(UZ
Kh'/Ne?
int responseCode=httpConnection.getResponseCode(); [6)`wi
if(responseCode>=400) >*B/Wy
{ DRj\i6-v
processErrorCode(responseCode); z(K[i?&
return -2; //-2 represent access is error 7*~ rhQ
} >jRz4%
N>'1<i?
#&5m=q$EI
String sHeader; D=o9+5Slw
?L+@?fVN
?4(uwXp
for(int i=1;;i++) 3zGxe-
{ HG5|h[4Gt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lmo>z'<
//Utility.log(in.readLine()); Ojr{z
sHeader=httpConnection.getHeaderFieldKey(i); M E4MZt:>
if(sHeader!=null) -Q<3Q_
{ G6]M~:<i
if(sHeader.equals("Content-Length")) -=s7Q{O8Z
{ o_vK4%y(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wVP{R3
break; <dLdSEw
} +\?#8U/k
} u&mB;:&
else `.>2h}op
break; E<>n0",
} (Lo<3a-]
} <RKh%4#~
catch(IOException e){e.printStackTrace ();} =YE"6iU
catch(Exception e){e.printStackTrace ();} blk~r0.2
:L&-
YFy5>*W
Utility.log(nFileLength); S%R:GZEf_
xT#j-T
%j^[%&pT
return nFileLength; =Bu d!
} .3Jggp
#x"4tI
r>eOq[z
//保存下载信息（文件指针位置） 0jro0f'
private void write_nPos() {ckA
{ mrS:||,_
try{ gmJiKuAL5
output = new DataOutputStream(new FileOutputStream(tmpFile)); Xv|~1v%s7
output.writeInt(nStartPos.length); k?o(j/
for(int i=0;i<nStartPos.length;i++) I)U|~N
{ ^ RU"v>
// output.writeLong(nPos); "|gNNmr
output.writeLong(fileSplitterFetch.nStartPos); APsd^J
output.writeLong(fileSplitterFetch.nEndPos); r2]:'O6
} vbXuT$
output.close(); 3&/5!zOg)
} (B.J8`h }
catch(IOException e){e.printStackTrace ();} t.v@\[{-
catch(Exception e){e.printStackTrace ();} S6*3."Sk
} LBk1Qw}-
6-{QU] #
RM|<(kq
//读取保存的下载信息（文件指针位置） >t.2!Z_RQ
private void read_nPos() N0,.cd]y`
{ l Ztq_* Fl
try{ 5#p [Q _
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C%85Aq*4
int nCount = input.readInt(); t \kI( G
nStartPos = new long[nCount]; {*bXO8vi((
nEndPos = new long[nCount]; EX7gTf#
for(int i=0;i<nStartPos.length;i++) \SkCsE#H
{ osB[KRT>("
nStartPos = input.readLong(); f>g>7OsD]
nEndPos = input.readLong(); !G.)%+Z
} $cHA_$ `
input.close(); MM"{ehd{^a
} i:0~%X
catch(IOException e){e.printStackTrace ();} Ev|2bk \
catch(Exception e){e.printStackTrace ();} #(FG+Bk
} ]i3 2-8%
6 :K~w<mMJ
44B)=p7
private void processErrorCode(int nErrorCode) ZY-W~p1:G
{ u~=>$oT't
System.err.println("Error Code : " + nErrorCode); y,v*jE
} ZC'(^liAp
`So*\#\T
;?"2sS!AHQ
//停止文件下载 UbE*x2N
public void siteStop() j yR9a!
{ a938l^@;s8
bStop = true; !>W _3Ea
for(int i=0;i<nStartPos.length;i++) \74+ cN
fileSplitterFetch.splitterStop(); LRW7_XYz
%Ak"d+OH4
23BzD^2a
} m!L&_Z|j
} c7.%Bn,
//负责部分文件的抓取 f5<qF ]Y/
**FileSplitterFetch.java 8Ih+^Y a
*/ 3yn>9qt
package NetFox; N|Mzj|i.
HWG5Ghu8,)
ZgVYC4=Q-\
import java.io.*; p@!{Sh
import java.net.*; _@wXh-nc
#Y`GWT1==
avrf]raM|
public class FileSplitterFetch extends Thread { */fmy|#
O$ui:<]dS
fl*]ua
String sURL; //File URL 7'uuc]\5>
long nStartPos; //File Snippet Start Position }a6tG
long nEndPos; //File Snippet End Position RI9&KS
int nThreadID; //Thread's ID ;2y3i5^k
boolean bDownOver = false; //Downing is over ?(UeWLC#
boolean bStop = false; //Stop identical >xb}AY;
FileAccessI fileAccessI = null; //File Access interface m?VA 1
c,-3+b
oMk6ZzZ,>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cL}}^
{ MgyV{`
this.sURL = sURL; ZE863M@.
this.nStartPos = nStart; T+7-6y+ d
this.nEndPos = nEnd; 6Ty;m>j
nThreadID = id; `3m7b!0k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J24<X9b
} 'F.Da#st!}
D&KRJQ/
,\ [R\s
public void run() C&?Z\$ -/
{ {?yZdL:m)
while(nStartPos < nEndPos && !bStop) |Am +f.
{ LldZ"%P
=0!PnBGYn
Dz4e.tvN
try{ ~Ry?}5&:
URL url = new URL(sURL); n?'I&0>M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %"kF i
httpConnection.setRequestProperty("User-Agent","NetFox"); uL| Wuq
String sProperty = "bytes="+nStartPos+"-"; yh~*Kt]9Ya
httpConnection.setRequestProperty("RANGE",sProperty); Ud@D%?A7
Utility.log(sProperty); .)J7 \z8m
tP/0_^m
_M[@a6?
InputStream input = httpConnection.getInputStream(); i[,9hp
//logResponseHead(httpConnection); IL*Ghq{/
>G`Uc&=
xv|?;Zf6w
byte[] b = new byte[1024]; tgk] sQY
int nRead; zY_?$9l0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) mk*r^k`a
{ <!@*2/Q]J]
nStartPos += fileAccessI.write(b,0,nRead); "QCtF55X&
//if(nThreadID == 1) DXFU~J*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]=Im0s
} SLI(;, s
/Mq9~oC
}.`no
Utility.log("Thread " + nThreadID + " is over!"); s}3g+T\l1w
bDownOver = true; DAYR=s
//nPos = fileAccessI.write (b,0,nRead); b2rlj6d
} ?fv5KdD
catch(Exception e){e.printStackTrace ();} VS.~gHx
} Jkf%k3H3I*
} F_C7S
PD,s,A
`X;'*E]e
//打印回应的头信息 ,v<GSiO
public void logResponseHead(HttpURLConnection con) 7nsn8WN[
{ (x)}k&B;
for(int i=1;;i++) <V?csx/eRd
{ @-B)a Z
String header=con.getHeaderFieldKey(i); al#BfcZW
if(header!=null) =17d7#-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0<ze'FbV]
Utility.log(header+" : "+con.getHeaderField(header)); Vc2(R^
else ,hO*W-a%1
break; 3:H[S_q
} S=f:-?N|
} UYLCzv~W
,oin<K
:`jB1rI
public void splitterStop() goa@e
{ /2s=;tA1
bStop = true; Hsdcv~Xr;l
} kD}w5 U
ZwzN=03T
u4eA++eT
} GvB;o^Wd
/w|!SZB
V= wWY*C
/* HGiO}|q:
**FileAccess.java ,>C`|
*//文件访问(定位，写) ;*J_V/&?
package NetFox; o54/r#~fi
import java.io.*; Yee% <<S
%2q0lFdcM
0gevn
public class FileAccessI implements Serializable{ 6y0CEly>3#
;xXD2{q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ffH]`N
RandomAccessFile oSavedFile; J]AkWEiCJ
long nPos; J=l\t7w
*#y9Pve
f*%Y]XL;%
public FileAccessI() throws IOException TWU[/>K
{ r$Tu``z \
this("",0); qpEK36Js
} XJSI/jpa@
&mPR[{
;#/Uo8
public FileAccessI(String sName,long nPos) throws IOException !_P-?u
{ #{8t ?v l
oSavedFile = new RandomAccessFile(sName,"rw"); +|K/*VVn`
this.nPos = nPos; [gkOwU=?
oSavedFile.seek(nPos); Zws[C
} 8MZ:=
lWyg_YO@
n1Z*wMwC
public synchronized int write(byte[] b,int nStart,int nLen) 8V?*Bz-4`
{ xo GX&^=
int n = -1; 7*MjQzg-P
try{ O$*\JL
oSavedFile.write(b,nStart,nLen); yDORL| E'
n = nLen; ?PSJQ3BC|
} Tfytc$aQ
catch(IOException e) "KHe6otmi_
{ I9ZJ"29
e.printStackTrace (); j>I.d+
} s$3WJ'yr
e~1$x`DH
77/j}Pxh
return n; }C'h<%[P
} 0l'"idra
ugy:^U
c#L.I
} b~td^
zI&).
k:yrh:JhB
/* C"cBlru8B
**SiteInfoBean.java .4%6_`E
*/ CubBD+hl*
package NetFox; ]vQU(@+I
JTS<n4<a
5T-CAkR{n
public class SiteInfoBean { 8b|m66#|
s~b!3l`gu
@|;XDO`k;
private String sSiteURL; //Site's URL +'`I]K>
private String sFilePath; //Saved File's Path Yw6d-5=:
private String sFileName; //Saved File's Name W5U;{5
private int nSplitter; //Count of Splited Downloading File !#TM%w
k:0nj!^4w>
*USzzLq
public SiteInfoBean() XJguw/[wm
{//nSplitter的缺省值为5 +rOfQ'lQ
//default value of nSplitter is 5 btDPP k'
this("","","",5); o%3VE8-
} j\%m6\{n|
=|O><O|
Aw,#oG {N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) feA(Rj
{ +V,Ld&r
sSiteURL= sURL; pP^"p"<s
sFilePath = sPath; E>L_$J-A-
sFileName = sName; HI!bq%TZ4
this.nSplitter = nSpiltter; 2O+fjs
Y}hz UKJ
hB1Gtc4n
} I`KBj6n
G_5E#{u
1vL$k[^&d
public String getSSiteURL() x67,3CLy?
{ )A*Sl2ew
return sSiteURL; ?t"bF:!
} n1@ Or=5
oh%/\Xu
wg{Y6XyH
public void setSSiteURL(String value) Mb\[` 4z
{ e*/ya8p?
sSiteURL = value; BDc "0XH
} c 6$n:
kOLS<>.
9 ?(P?H
public String getSFilePath() !k0t (.
{ :}[[G2|9
return sFilePath; TM$Ek^fQ.
} mqv!"rk'w
F/chE c V
S$%Y{
public void setSFilePath(String value) ]zR,Y= #
{ ~glFB`?[
sFilePath = value; 8+U':xR
} 90]{4]y;
ealh>Y
[0-zJy|,
public String getSFileName() Jm{~H%
{ <#5`%sa '
return sFileName; hP]zC1s
} %{K6
u9^R ?y
_.ELN/$-
public void setSFileName(String value) t.tdY
{ "Qxn}$6-
sFileName = value; :O{oVR
} `Ef&h V
^><B5A>;
,O}2LaK.O
public int getNSplitter() YcJ2Arml
{ js8GK
return nSplitter; "K*+8IO2
} WX9pJ9d
)bPF@'rF2
-"Q[n,"Y
public void setNSplitter(int nCount) Y'S9
{ X>6VucH{\
nSplitter = nCount; 9,;+B8-A
} R@H}n3,
} BlvNBB1^
!WReThq
^Wz3 q-^
/* [j`-R 0Np
**Utility.java Cb/?hT
*/ @5-+>\Hd^t
package NetFox; p; ZEz<M
Q|W!m0XO
:j m|)
public class Utility { 7OOod1
tHo0q<.oX
5`3f"(ay/
public Utility() .5m^)hi
{ ^. i;,
MB,P#7|
f3]u-e'b
} H9Pe,eHs
1yIo'i1
//线程睡眠 .DkDMg1US
public static void sleep(int nSecond) L5*,l`lET
{ "yCek
try{ A*:(%!
Thread.sleep(nSecond); |fk,&5s
} @9rmm)TZ
catch(Exception e) NX*9nwp^
{ Eh)VU_D
e.printStackTrace (); "rA:;ntz
} fJ3qL#'
} YMx zj
;Q.g[[J/p
//日志 {@u}-6:wAT
public static void log(String sMsg) m 5NF)eL
{ ;,h*s,i
System.err.println(sMsg); IBzHXa>75
} ptmPO4f
Ueyt}44.e2
D{,B[5
public static void log(int sMsg) "lf_`4
{ ]41G!'E=
System.err.println(sMsg); uhLg2G^h
} ^JMSe-
} :6z0Ep"
BVC{Zq6hi
Fq5);sX=
/* 0OMyE9jJJ
**TestMethod.java []Z| *+=Q
*/ (;T;?v`-
package NetFox; 1LjYV
s geP`O%
<>JDA(F"
public class TestMethod { >gr6H1
!P!|U/|c
[VPqI~u5)
public TestMethod() ytmlG%
{ ///xx/weblogic60b2_win.exe `q exEk@S
try{ V_(?mC
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dg#Ab8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b['TRYc=:
SiteFileFetch fileFetch = new SiteFileFetch(bean); ):+H`Hcm
fileFetch.start(); 79%${ajSI
} /d >fp
catch(Exception e){e.printStackTrace ();} Z3R..vy8
?#kI9n<O
-c=IO(B/
} T[XI
5.|rzk>
w'5~GhnP+
public static void main(String[] args) xL>0&R
{ =I/J !}.
new TestMethod(); ZF;S}1
} 5Tpn`2F
} |U^ ff^]
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