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)); +FWkhmTv
} &\$l%icuo
for(int i=0;i<nEndPos.length-1;i++) D 5qCn^R
{ uOqWMRsoi
nEndPos = nStartPos[i+1]; MEQ:[;1
} Z%Nl<i
nEndPos[nEndPos.length-1] = nFileLength; -O2ZrJ!q
} szC~?]<YY
} eyZ /%4'q
x8sSb:N
PF-7AIxs"
//启动子线程 O4kBNUI/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 63d' fgVp
for(int i=0;i<nStartPos.length;i++) Ch`XwLY9
{ +'H_sMmi{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zA&lJD$0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5uK:f\y)l
nStartPos,nEndPos,i); DYU+?[J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M`ETH8Su=
fileSplitterFetch.start(); j(!M
} ]k%Yz@*S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \+E{8&TH'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /a\6&Eb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A e&t#,)
nEndPos = " + nFileLength); #N%xr'H
// fileSplitterFetch[nPos.length-1].start(); bE2^sx`(
q28i9$Yqj\
]l>)Di#*o
//等待子线程结束 BF2,E<^A
//int count = 0; ,V3P.ni]
//是否结束while循环 aE6I|6W?
boolean breakWhile = false; N.C<Mo
&AmTXW
mxhO:.l
while(!bStop) 1@C0c%
{ 2H_|Attoi
write_nPos(); <J@Y=#G$2
Utility.sleep(500); sB ]~=vUP
breakWhile = true; E)m{m$Hb
716JnG>
T9\wkb.
for(int i=0;i<nStartPos.length;i++) |k:MXI
{ 7=t4;8|j;
if(!fileSplitterFetch.bDownOver) GFOd9=[
{ ywpk\
breakWhile = false; "W;GvI
break; )_OKw?Zi
} mc;Z#"kf
} Y@N}XH<4R
if(breakWhile) d6-a\]gF
break; ozF>2`K }
&,2h=H,M
xSZgQF~
//count++; YYHtd,0\+
//if(count>4) quHq?oXV,
// siteStop(); wQ qI@
} Y 9]
^4_)a0Kcm,
kDS
System.err.println("文件下载结束！"); Oemi}
} 6Yebc_, R
catch(Exception e){e.printStackTrace ();} .{x-A{l
} Vo<V!G{
R>U0W{1NO
$-m@cObw!.
//获得文件长度 qz"di~7
public long getFileSize() vFLQq,?Nh
{ e5_a.c
int nFileLength = -1; cq+|fg~Yy
try{ "S.5_@?
URL url = new URL(siteInfoBean.getSSiteURL()); 2Jl6Xc8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %KK6}d#
httpConnection.setRequestProperty("User-Agent","NetFox"); ^%V'l-}/
hIu;\dfwk
sL|*0,#K
int responseCode=httpConnection.getResponseCode(); wgxr8;8`q
if(responseCode>=400) 6/Y3#d
{ Yo3my>N&g
processErrorCode(responseCode); _Q,`Qn@|BD
return -2; //-2 represent access is error )WavG1
} o<bZ.t
ec+&K?T
XQ]noaU
String sHeader; hdt;_qa
G=Hvh=K(
n@ lf+
for(int i=1;;i++) =B@+[b0Z
{ o^FlQy\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H)z}6[`
//Utility.log(in.readLine()); _SdO}AiG
sHeader=httpConnection.getHeaderFieldKey(i); "vI:B}
if(sHeader!=null) z ^t6VFM
{ "/[xak!g
if(sHeader.equals("Content-Length")) V:HxRMF2X
{ _0dm?=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xR}^~14Bz
break; TG9 a1q
} 5e=9~].7
} N\{Xhr7d
else Vc0C@*fVM
break; }-QFMPXhG
} ;Gixu9u'
} \6AYx[|
catch(IOException e){e.printStackTrace ();} 6BK-(>c(6
catch(Exception e){e.printStackTrace ();} Em8q1P$tm>
2GeJ\1k
OZ>w.$ue
Utility.log(nFileLength); Nki08qZ[
Aiyx!Q6vT
Kv(2x3("
return nFileLength; RlW0U-%u
} W;%$7&+0
mQ(6ahD U
<&JK5$l<X
//保存下载信息（文件指针位置） NMJX `
private void write_nPos() i2.g}pM.A
{ b)ytm=7ha
try{ ]mIcK
output = new DataOutputStream(new FileOutputStream(tmpFile)); EHI%QT
output.writeInt(nStartPos.length); Z*uv~0a>9Q
for(int i=0;i<nStartPos.length;i++) 4-j3&(
{ (j<FS>##
// output.writeLong(nPos); 3s%Kw,z
output.writeLong(fileSplitterFetch.nStartPos); RHO|g0
output.writeLong(fileSplitterFetch.nEndPos); E3..$x-/
} zD}@QoB
output.close(); Y=G9|7*lO
} lL8pIcQW
catch(IOException e){e.printStackTrace ();} jGm`Qg{<
catch(Exception e){e.printStackTrace ();} o,qq*}=
} &~4;HjS
T'i^yd}*v
+lYo5\1=
//读取保存的下载信息（文件指针位置） tL#~U2K
private void read_nPos() 6chcpP0
{ f%,Vplb
try{ 8-#_xsZ^;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;*{"|l qe
int nCount = input.readInt(); y J|/^qs
nStartPos = new long[nCount]; ~Un+Zs%24
nEndPos = new long[nCount]; \p4>onGI
for(int i=0;i<nStartPos.length;i++) *r)/Vx`S
{ 7Gh+EJJ3I
nStartPos = input.readLong(); 7];AB;0"
nEndPos = input.readLong(); xdLMy#U2
} '@0Z#A
input.close(); 1j_gQ,'20
} 9ZJn 8ki
catch(IOException e){e.printStackTrace ();} iY,FfuE
catch(Exception e){e.printStackTrace ();} {<}9r6k;f
} AT6o~u!WU
)k^y<lC2a
`{KdmWhW
private void processErrorCode(int nErrorCode) y:HH@aa)
{ bmzY^ %a
System.err.println("Error Code : " + nErrorCode); !jQj1QZR`
} *SK`&V
wo+b":
m{gw:69h
//停止文件下载 u~xfI[8C
public void siteStop() +dG3/vV
{ A+=K<e
bStop = true; Y&uwi:_g
for(int i=0;i<nStartPos.length;i++) =vs]Kmm
fileSplitterFetch.splitterStop(); FoQy@GnM5
9oU1IT9
!AXt6z cZ
} ]*Cq'<h$
} 5O%?J-Hp
//负责部分文件的抓取 }`pxs
**FileSplitterFetch.java ^O3i)GO
*/ _. &N@k
package NetFox; "h5.^5E6
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import java.io.*; JKz]fgOd$
import java.net.*; $KVCEe!X
qKD Nw8>
:V0sKg|sS
public class FileSplitterFetch extends Thread { P:>]a$Is
n_{az{~
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String sURL; //File URL nN2huNTf:
long nStartPos; //File Snippet Start Position G3o`\4p
long nEndPos; //File Snippet End Position jdIAN
int nThreadID; //Thread's ID 5uX-onP\[
boolean bDownOver = false; //Downing is over Z,oCkv("n
boolean bStop = false; //Stop identical JRR,ooN*i
FileAccessI fileAccessI = null; //File Access interface Bm5\*Xd1(
[(2XL"4D
+i~kqiy.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N;v]ypak
{ UP7?9\
this.sURL = sURL; aL&nD1f=!-
this.nStartPos = nStart; '!F'B:
this.nEndPos = nEnd; ,u=+%6b)A
nThreadID = id; Kk).KgR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "vX\Q rL
} @A|#/]S1
r&+w)U~
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public void run() 2;K2|G7
{ V KxuK0{
while(nStartPos < nEndPos && !bStop) g2?yT ?
{ p<<dj%
V`8\)FFG
Q ZC\%X8j
try{ Ciy%7_~\
URL url = new URL(sURL); a2[rY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G+&pq
httpConnection.setRequestProperty("User-Agent","NetFox"); 4peRbm
String sProperty = "bytes="+nStartPos+"-"; k=cDPu -
httpConnection.setRequestProperty("RANGE",sProperty); -Iis/Xw:
Utility.log(sProperty); [FZq'E"87
lD{*Z spz
v o4U%
InputStream input = httpConnection.getInputStream(); s\< @v7A
//logResponseHead(httpConnection); EywBT
.K]Uk/W
6FN#Xg
byte[] b = new byte[1024]; qi ">AQpp
int nRead; E3] 8(P%D-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0cDP:EzR;
{ >=:^N-a
nStartPos += fileAccessI.write(b,0,nRead); <xe_t=N
//if(nThreadID == 1) e,r7UtjoxR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~N2=44e
} \._|_+HiW
2C1NDrS;}
[RF]lM]w
Utility.log("Thread " + nThreadID + " is over!"); Wffz&pR8
bDownOver = true; 7<Qmpcp =
//nPos = fileAccessI.write (b,0,nRead); WEJ-K<A(
} 'c_K[p$
catch(Exception e){e.printStackTrace ();} 9 r&JsCc
} +,]VXH<y
} K- $,:28
6^!fuIZ;_
T"aE]4_
//打印回应的头信息 y=.bn!u}z
public void logResponseHead(HttpURLConnection con) ?20R\ ]U
{ Y%?*Lj|
for(int i=1;;i++) Yg,;l-1
{ ^}{x).
String header=con.getHeaderFieldKey(i); nMZ)x-
if(header!=null) 9e c},~(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); YRCs&tgs
Utility.log(header+" : "+con.getHeaderField(header)); gWoUE7.3`
else 5@-H8*
break; x$bUd 9
} vj344B
} VX82n,'=t
FUlhEH
"*.N'J\
public void splitterStop() zsd1n`r
{ qTN%9!0@9
bStop = true; y4LUC;[n
} ><Zu+HX
tXH;4K@
H17I"5N
} E>f{j:M
fISK3t/=C
1^2Q`~,g
/* 1+WVh7gF
**FileAccess.java Rw%?@X3m]
*//文件访问(定位，写) ^=n7E
package NetFox; $+_1F`
import java.io.*; hc+B+-,
R ZQH#+*t}
ux)*B}/xh
public class FileAccessI implements Serializable{ DU$#tg}{
^/#G,MxNy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Um6}h@>
RandomAccessFile oSavedFile; <Q/)SN6_E
long nPos; fn=A_ i
{_\cd.AuT
H$C*&p
public FileAccessI() throws IOException 0VSIyG_Z
{ 1(dKb
this("",0); kx?Yin8K
} (lVMy\
DAP/
Ao$k[#px
public FileAccessI(String sName,long nPos) throws IOException D|*w6p("z
{ =>`zk^
oSavedFile = new RandomAccessFile(sName,"rw"); $b1>,d'oz
this.nPos = nPos; c8"Qmy
oSavedFile.seek(nPos); mV`R'*1UC
} k|?[EWIi^
xh$yXP0/
2#R$-*;#
public synchronized int write(byte[] b,int nStart,int nLen) U364'O8_
{ <tFq^qB
int n = -1; 1:](=%oM&k
try{ 8R!-,I"$
oSavedFile.write(b,nStart,nLen); 4RB%r
n = nLen; #eOHe4Vt
} X+N5iT
catch(IOException e) IRx%L?
{ } SWp~3P
e.printStackTrace (); )MF@'zRK
} r^}0qO,XM
XZARy:+bc
UWC4PWL,>C
return n; ah,f~.X_|
} = NZgbl
'LPyh ;!f
<i</pA
} u1M8nb
ZAn @NA=
RVttk )Ny
/* YZ+G7D>
**SiteInfoBean.java NL$z4m0
*/ o/o6|[=3
package NetFox; JS^DyBXc
6c-3+,Y"#
ydYsmTr
public class SiteInfoBean { 0H>gMXWE]
$Bz};@
6R<+_e+v
private String sSiteURL; //Site's URL \XV8t|*
private String sFilePath; //Saved File's Path ?SFQx\/
private String sFileName; //Saved File's Name Gm:s;w-;v
private int nSplitter; //Count of Splited Downloading File .(q'7Q Z/
27ZqdHd
CYy=f-
public SiteInfoBean() m8{8r>6*
{//nSplitter的缺省值为5 +S0aA Wal
//default value of nSplitter is 5 F*@2)
this("","","",5); {Z8GG
} 56<UxIa~
Itr4Pr
Gh=I2GSo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6WZffB{-TK
{ aUEr& $
sSiteURL= sURL; GD.Ss9_h1
sFilePath = sPath; "NA<^2W@J
sFileName = sName; %Hd[,duwO
this.nSplitter = nSpiltter; ^@*`vz^_
2kVZlt'y
d%0Gsga}
} r'{N_|:vv
G8+&fn6
rIFW1`N}i
public String getSSiteURL() o|h=M/
{ f4P({V
return sSiteURL; QyVAs;
} */IiL%g4u
1!.-/
R`<2DC>h9
public void setSSiteURL(String value) 8k-]u3
{ tlp,HxlP
sSiteURL = value; Rmmu#-{Y
} Wx]Xa]-
o+=wQ$"tP
H;\C7w|
public String getSFilePath() wl]3g
{ m_0y]RfG
return sFilePath; \7b, Mz!
} k^;n$r"i5
ni{'V4A
M;<!C%K>
public void setSFilePath(String value) i,ZEUdd*_
{ y*^UGJC:
sFilePath = value; e%)iDt\j
} O>pX(DS L
.5a>!B.I
,==_u
public String getSFileName() Hj r'C?[
{ rmA?Xlh\
return sFileName; N\__a~'0p
} 7uc\AhOk6
ZT!8h$SE:
\54B
public void setSFileName(String value) b3-j2`#
{ WT,I~'r=S
sFileName = value; (K=0c6M3=
} a~jb%i_
%pq.fZI
F_:zR,P%#
public int getNSplitter() 1ygEyC[1
{ N 5Om~D
return nSplitter; `ZEFH7P
} f> Jj5he/
r]cq|Nv8:
J@/4CSCR]
public void setNSplitter(int nCount) HL"c yxe
{ Vv+nq_
nSplitter = nCount; 9k71h`5
} *O'|NQhNx>
} T2Z$*;,>T
}:faHLYT
:Y/aT[
/* n(Nu
**Utility.java Kt*b) <
*/ ?aTH<
package NetFox; B(Yg1jAe
q-Z<.GTq
Wo&22,EB
public class Utility { K>.}>)0
?9{^gW4|
vaF1e:(
public Utility() 3HtM<su*h
{ xSN;vrLHR
=I'iD0eR
[VXQ&
} }Y!V3s1bm
,X_3#!y
//线程睡眠 BTr oe=R
public static void sleep(int nSecond) TU_'1
{ 2i6=g<
try{ `m(ZX\W]
Thread.sleep(nSecond); gnN>Rl 5_
} cu}(\a
catch(Exception e) ek5j;%~g1
{ moFrNcso
e.printStackTrace (); Ynf "g#(
} y]{b4e
} BDfMFH[1
.a2R2~35
//日志 Nk-xnTZ"
public static void log(String sMsg) >)Qq^?U
{ z@IG"D
System.err.println(sMsg); n5~Dxk
} _`=qc/-0
5,XEN$^
bl!pKOY
public static void log(int sMsg) gLt6u|0q
{ V$DB4YM1k
System.err.println(sMsg); 7n .A QII
} %9zpPrWF
} ]EF"QLNN(
:fRta[
uYs45 G
/* 8?L-3/
**TestMethod.java IW nG@!
*/ ]GRVU
package NetFox; ~-sgk"$
#QlxEs#%
]{i0?c
public class TestMethod { @+~URIG)
&0*l:uw
PQ!'<
public TestMethod() Ye|gW=FUR
{ ///xx/weblogic60b2_win.exe R+0fs$su
try{ dh{py
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ok,O/|E}?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5![ILa_
SiteFileFetch fileFetch = new SiteFileFetch(bean); se3EI1e
fileFetch.start(); C-49u<;,
} g;R
catch(Exception e){e.printStackTrace ();} &9v8
xK[[b
dcemF
} #Z]Cq0=
qe1>UfY
3:sc%IDP
public static void main(String[] args) p `oB._ R
{ MftaT5
new TestMethod(); "9c!p
} KIuj;|!q
} 9nO&d(r g
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