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)); GDLw_usV
} xvl$,\iqE
for(int i=0;i<nEndPos.length-1;i++) P<pv@l9)
{ ~b_DFj
nEndPos = nStartPos[i+1]; UytMnJ88
} Lu#qo^
nEndPos[nEndPos.length-1] = nFileLength; ,z&S;f.f
} |))NjM'ZBl
} Lc!2'Do;
}nrjA0WN
|=;hQ2HyF
//启动子线程 PVb[E03
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G+dq */
for(int i=0;i<nStartPos.length;i++) sq$v6x sl
{ OnTe_JML
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5dj" UxH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]\*^G@HA2
nStartPos,nEndPos,i); _xKn2?d8g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7)2K6<q
fileSplitterFetch.start(); F`g(vD>
} tSHW"R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =MNp;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UhH#>2r_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HA'~1$#z
nEndPos = " + nFileLength); ;UQza ]i
// fileSplitterFetch[nPos.length-1].start(); `Gio 2gl9
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y_m+&Oe
//等待子线程结束 HzTmNm)
//int count = 0; ,AnD%#o
//是否结束while循环 w/|&N>ZOx
boolean breakWhile = false; K6DN>0sY
=|oi0
%]+R>+
while(!bStop) BqNsW (+
{ 6ll!7U(9(
write_nPos(); !!C/($
Utility.sleep(500); 8}|et~7!
breakWhile = true; U3_${
-8l<5g7
&M13F>!
for(int i=0;i<nStartPos.length;i++) V\`Z|'WIQD
{ W,4!"*+
if(!fileSplitterFetch.bDownOver) >9H^r\
{ ^_]ZZin
breakWhile = false; <Kt_ oxK,
break; {SV/AN
} Z"8lW+r*
} RHUZ:r
if(breakWhile) >~o-6g
break; &jJu=6 U B
[xqV`(vM
C:B7%<
//count++; KlT:&1SB9
//if(count>4) Sf?;j{?G
// siteStop(); Vuz.b.,i`
} =F+v+zP7P
~nA k-toJ
O},}-%G
System.err.println("文件下载结束！"); ed6@o4D/kf
} i(4<MB1a
catch(Exception e){e.printStackTrace ();} @j\:K<sk
} :+\0.\K0!
.OdtM Xy
Z|t=t"6"
//获得文件长度 s+:|b~
public long getFileSize() n\+c3
{ afrF%!
int nFileLength = -1; $7q3[skH
try{ CXq[VYM&X
URL url = new URL(siteInfoBean.getSSiteURL()); 3-/|G-4k7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Go%Z^pF3CO
httpConnection.setRequestProperty("User-Agent","NetFox"); _/1/{
G'JHimP2j
{w2] Is2F
int responseCode=httpConnection.getResponseCode(); HPphTu}`
if(responseCode>=400) |^Iox0A
{ O=jLZ2os
processErrorCode(responseCode); Jxvh;
return -2; //-2 represent access is error PK+sGV
} ${T/b(NM
Ja6KO2}p
H~FI@Cf$L
String sHeader; 3X gJZ
Ksx-Y"
S>oEk3zlw
for(int i=1;;i++) xSudDhRP
{ Xl4}S"a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LhL |ETrJ
//Utility.log(in.readLine()); owIpn=8|Q
sHeader=httpConnection.getHeaderFieldKey(i); _V"0g=&Hc
if(sHeader!=null) <&\ng^Z$
{ 0q5J)l:
if(sHeader.equals("Content-Length")) :qE.(k1@5
{ 1ui)Hv=h*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); UBwl2Di
break; f./K/
} ':n`0+Eh
} e0(/(E:
else ov+{<0Q
break; Wep^He\:
} j:%,lcF
} $M}"u[Qq
catch(IOException e){e.printStackTrace ();} }2]|*?1,
catch(Exception e){e.printStackTrace ();} =F@ +~)_
*H/>96
xeF>"6\
Utility.log(nFileLength); Zv@qdY<:
TnQ>v{Rx
P&Keslk
return nFileLength; Ll|-CY $
} :'T+`(
2^B_iyF;
Bc8&-eZ,
//保存下载信息（文件指针位置） J.UNw8z
private void write_nPos() c4AJ`f.5
{ naR<
try{ d`/8Q9tQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); IP`lx
output.writeInt(nStartPos.length); OH/9<T?
for(int i=0;i<nStartPos.length;i++) hNXZL>6
{ *J4!+GD
// output.writeLong(nPos); KtaoOe
output.writeLong(fileSplitterFetch.nStartPos); {dF@Vg_n
output.writeLong(fileSplitterFetch.nEndPos); L-Q8iFW'
} #zP-,2!r
output.close(); @V 'HX
} $+80V{J#
catch(IOException e){e.printStackTrace ();} DzR,ou
catch(Exception e){e.printStackTrace ();} ! yJ0Am>
} 0BXr[%{`
eay|>xa2
Sn[xI9}O
//读取保存的下载信息（文件指针位置） DQ8/]Z{H
private void read_nPos() neU=1socJ
{ p<r^{y
try{ ;y(;7n_ a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $2W#'_K+
int nCount = input.readInt(); syr0|K[
nStartPos = new long[nCount]; k'8q/]
nEndPos = new long[nCount]; SA'g`
for(int i=0;i<nStartPos.length;i++) ug,AvHEnB
{ f(y+1
nStartPos = input.readLong(); [0Xuo
nEndPos = input.readLong(); gs1yWnSv5
} >T;!Z5L1
input.close(); $TK*w8@:
} z6w'XA1_+t
catch(IOException e){e.printStackTrace ();} bhD-;Y!6;
catch(Exception e){e.printStackTrace ();} !Q"L)%)'A
} -Y524
}aOqoi7w
8Ay7I
private void processErrorCode(int nErrorCode) 8(Az/@=n
{ ~g!!#ad
System.err.println("Error Code : " + nErrorCode); :WRD<D_4
} uzxwJs'fz
1{M?_~g4
y CHOg
//停止文件下载 waMV6w)<
public void siteStop() i1x4$}
{ pT=^o
bStop = true; [.>=>KJ_
for(int i=0;i<nStartPos.length;i++) !BVCuuM>w
fileSplitterFetch.splitterStop(); 'TYO-'aC
-n7@r
lq.:/_m0
} fDDpR=
} d3znb@7
//负责部分文件的抓取 ovN3.0tAI
**FileSplitterFetch.java HsYzIQLL
*/ Y[e.1\d'
package NetFox; 1)c{;x&W
#r9\.NA!
"iEnsP@'Wg
import java.io.*; Aq(cgTNW
import java.net.*; I'IFBVhaYn
07SW$INb
ga|<S@u?}
public class FileSplitterFetch extends Thread { %( OP [
/\Nc6Z/ L
FV9{u[3m
String sURL; //File URL P]m{\K
long nStartPos; //File Snippet Start Position D 6'd&U{_
long nEndPos; //File Snippet End Position @N '_qu
int nThreadID; //Thread's ID Z4G%Ve[
boolean bDownOver = false; //Downing is over 1^^{;R7N
boolean bStop = false; //Stop identical ZNH-0mk
FileAccessI fileAccessI = null; //File Access interface h<LS`$PK;E
~Q=;L>Qd
97 SS0J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oC" [rn
{ {$EX :ID
this.sURL = sURL; a)W|gx6Y
this.nStartPos = nStart; Y 22Ai
this.nEndPos = nEnd; pF6u3]
nThreadID = id; * 4J!@w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "tl{HM5u
} PI L)(%X
vFHeGq70j
TAh'u|{u2
public void run() H,c1&hb/w
{ )-X8RRw'
while(nStartPos < nEndPos && !bStop) _886>^b@
{ 1VYH:uGuAU
[<i3l'V/[
5 `TMqrk
try{ M>=@Z*u/+
URL url = new URL(sURL); ZzK^bNx)0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RUr ~u
httpConnection.setRequestProperty("User-Agent","NetFox"); zU[o_[+7^
String sProperty = "bytes="+nStartPos+"-"; dlyGgaV*X
httpConnection.setRequestProperty("RANGE",sProperty); kT
Utility.log(sProperty); *b~8`Opa`
Uy=yA
>7@,,~3
InputStream input = httpConnection.getInputStream(); #SHJ0+)o
//logResponseHead(httpConnection); /*gs]
{QG6ldI
CV HKP[-
byte[] b = new byte[1024]; %wl:>9]
int nRead; v9J1Hha#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w!*ZS~v/r
{ gHh(QRA
nStartPos += fileAccessI.write(b,0,nRead); "E7<S5cr
//if(nThreadID == 1) >lmqPuf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aVHID{Gf Z
} +uF}mZS^
\a0{9Xx F
ir}*E=*
Utility.log("Thread " + nThreadID + " is over!"); u0)O Fz
bDownOver = true; Vxrj(knck,
//nPos = fileAccessI.write (b,0,nRead); tHaHBx1P
} 6|Dtx5 "r
catch(Exception e){e.printStackTrace ();} [ {"x{;
} R%LFFMVn
} &b~X&{3,
cb'Ya_
s8:epcL`A
//打印回应的头信息 Msvs98LvW
public void logResponseHead(HttpURLConnection con) vC&0UNe$
{ 1LFad>`
for(int i=1;;i++) GYy8kp84
{ 3,Z;J5VL4!
String header=con.getHeaderFieldKey(i); )y:M8((%
if(header!=null) x_8sV?F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \aof
Utility.log(header+" : "+con.getHeaderField(header)); 6qQ_I0f
else \+Qd=,!i(
break; V!*1F1
} [< 9%IGH
} fb0)("_V
%qJgtu"8
Qu/f>tJN;
public void splitterStop() _&G_SNa
{ +5-|6
bStop = true; 6f0o'
} >8{{H"$;(
bCTN^
3P75:v
} O|Vc
D\ZH1C!d
Tw%1m
/* Z;u3G4XlF
**FileAccess.java w?3ww7yf`
*//文件访问(定位，写) _"H\,7E
package NetFox; &RuTq6)r
import java.io.*; $uwz`N:
b'FTyi
cJ?,\@uuP
public class FileAccessI implements Serializable{ FW2x
(!m6>m2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <j
RandomAccessFile oSavedFile; 4uE)*1
long nPos; :Eh}]_
GXLh(d!C
uZf 6W<a
public FileAccessI() throws IOException ~tL:r=
{ B<myt79F_[
this("",0); JSq3)o9?/
} LO%e1y
FwKY;^`!d
9A{D<h}yk
public FileAccessI(String sName,long nPos) throws IOException n}9<7e~/
{ 9I5AYa?
oSavedFile = new RandomAccessFile(sName,"rw"); | Wj=%Ol%o
this.nPos = nPos; '8R5Tl
oSavedFile.seek(nPos); $AZ=;iP-
} g;q.vHvsc"
@b2?BSdUp
1Xh@x
public synchronized int write(byte[] b,int nStart,int nLen) fwx^?/5j
{ t0xE&#4
int n = -1; W}7Uh b
try{ 6o]{< T/'
oSavedFile.write(b,nStart,nLen); ',|OoxhbK
n = nLen; Ma{@b$>
} ETH ($$M
catch(IOException e) y_Gs_xg
{ 2S:B%cj9m
e.printStackTrace (); m'G=WO*%
} ]4')H;'y
RV]QVA*i
U![$7k>,pr
return n; Dbx zqd
} n0K+/}m
J_XkQR[Y
B1I{@\z0G
} @yQ1F> t
xU{0rM"
dB&<P[$+8
/* FKe/xz
**SiteInfoBean.java ,T^A?t
*/ DqI"B
package NetFox; Cnc=GTRi
Uw5&.aqn.b
7bGOE_r
public class SiteInfoBean { >pol'=
cN2Pl%7
n Jz*}=
private String sSiteURL; //Site's URL uHZjpMoM
private String sFilePath; //Saved File's Path q)@;8Z=_c
private String sFileName; //Saved File's Name /r&4< @
private int nSplitter; //Count of Splited Downloading File -J'ked
pp#!sRUKPV
%k"hzjXAw
public SiteInfoBean() TgLr4Ex
{//nSplitter的缺省值为5 "WPWMQ+
//default value of nSplitter is 5 q+;lxR5D
this("","","",5); RZ9_*Lq7+
} YXF^4||j.c
jCx*{TO
\O~WMN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?}uvpB1}
{ "}[ ]R
sSiteURL= sURL; OB+cE4$
sFilePath = sPath; kA2)T,s74
sFileName = sName; HFYe@2r
this.nSplitter = nSpiltter; RN&8dsreZp
`USze0"t0:
Q2m 5&yy@s
} .G<Or`K^i
iHdX
<P*7u\9&
public String getSSiteURL() tqt~F2u
{ Xp6Z<Z&N
return sSiteURL; wk=s3^
} x6\^dVR}
)1YGWr;ykS
plzwk>b_
public void setSSiteURL(String value) 4VA]S
{ ?H{?jJj$H
sSiteURL = value; O!F"w!5@
} jC-`u-_'j
i4SWFa``
a6d|Ps.\!
public String getSFilePath() f?@M"p@T
{ ?f5||^7
return sFilePath; .Rb4zLYL*w
} '&]6(+I>
d%!yFix;<
L<Z2
public void setSFilePath(String value) ?Qpi(Czbpq
{ e&mTaCLG
sFilePath = value; @ L/i
} -H5-6w$
#TgP:t]p
*JWPt(bnI
public String getSFileName() cvpZF5mL]U
{ Sx_j`Cgy
return sFileName; n@oSLo`k,`
} |>Pv2
%P*b&H^0
sBE@{w%
public void setSFileName(String value) E /ycPqD
{ On+0@hh
sFileName = value; j{m{hVa
} PhmtCp0-7-
/sSif0I24
C+C1(b;1
public int getNSplitter() e.|t12)L "
{ :yOJL [x
return nSplitter; pQm-Hr78j
} v1NFz>Hx
,`$2
(<|1/^~=
public void setNSplitter(int nCount) q}&+{dN\1
{ You~ 6d6Om
nSplitter = nCount; $K1)2WG
} L$ju~0jl)%
} DVBsRV)/
NVDvd6
(Q|Y*yI
/* z2dW)_fU$
**Utility.java NE@P8pQ>
*/ %1i *Y*wg
package NetFox; .n}k,da@(
I=8MLv
l-'\E6grdH
public class Utility { ?&b"/sRS
z)*\njYe
1| xKb(_l
public Utility() OJLyqncw
{ YgkQF0+
ksqb& ux6
fp"GdkO#}i
} R1:7]z0B
`u8=~]rblj
//线程睡眠 y$?O0S%F
public static void sleep(int nSecond) Z Mf,3
{ O$Dj_R#
try{ T%2%*oa
Thread.sleep(nSecond); VmTgD96
} &y7~
catch(Exception e) dQAo~]B
{ 2-wgbC5
e.printStackTrace (); 6c[ L*1
} Sr6?^>A@t
} wq#'o9s,
=ZARJ40L
//日志 `6G:<wX
public static void log(String sMsg) u$1^=
{ .wuRT>4G)G
System.err.println(sMsg); 7"k\i=
} yL3F
oeG?2!Zh
CSE!Abg
public static void log(int sMsg) w"h'rw
{ zvbz3a
System.err.println(sMsg); EJTa~
} K`cy97
} h56s~(?O
zXeBUbVi
MAG/7T5
/* C2K<CDVw
**TestMethod.java 3;EBKGg|
*/ elb}] +
package NetFox; qo}u(pOj|
bg,VK1
$/P\@|MqYQ
public class TestMethod { 8EZ,hY^
D+Z,;XZ
vP/sG5$x
public TestMethod() ;DI"9
{ ///xx/weblogic60b2_win.exe ]iiB|xT
try{ wafws*b%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `>{S?t<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yTU'voE.|
SiteFileFetch fileFetch = new SiteFileFetch(bean); wW'.bqA
fileFetch.start(); -.7UpDg~
} <D(|}5qR
catch(Exception e){e.printStackTrace ();} ~fly6j|u
L(kW]
cN#f$
} ;UWp0d%
x/#.%Ga#T
?}U l(
public static void main(String[] args) eLop}*k
{ o%73M!-
new TestMethod(); hKFB=U
} m\J"P'=
} 7e@Bkq0)
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