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)); i`2X[kc
} ]{<`W5b/
for(int i=0;i<nEndPos.length-1;i++) T)NnWEB
{ }7H8Y}m
nEndPos = nStartPos[i+1]; 1TvR-.e
} L9=D,C~
nEndPos[nEndPos.length-1] = nFileLength; :W\xZ
} $MT'ZM
} \|}dlG
+s'qcC
Wqu][Wa[Z
//启动子线程 0H-~-z8Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; UHEn+Tc>
for(int i=0;i<nStartPos.length;i++) Z$? Ql@M
{ iJrF$Xw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9O+><x[i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DGwN*>X
nStartPos,nEndPos,i); 6O>GVJbw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =a<};X
fileSplitterFetch.start(); %;E/{gO
} >7VOytc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vNhi5EU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rK%A=Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /@<Pn&Rq
nEndPos = " + nFileLength); WmRx_d_
// fileSplitterFetch[nPos.length-1].start(); Qw ukhD7
9aR-kcvJIJ
lKMOsr@l
//等待子线程结束 G' ~Z'
//int count = 0; oT4A|M
//是否结束while循环 PSO9{!
boolean breakWhile = false; `;ofQz4
DB'd9<
d_j% ,1-#
while(!bStop) 1N_Gk&
{ )5}=^aqd
write_nPos(); G $TLWfm
Utility.sleep(500); -Cjc~{B>7X
breakWhile = true; S0\;FmLIc
w(QU'4~
K 9ytot
for(int i=0;i<nStartPos.length;i++) (6R^/*-o
{ <6]TazW?S
if(!fileSplitterFetch.bDownOver) Fq6sl}b(On
{ :Rh?#yO5
breakWhile = false; 5U&b")3IT!
break; 2g elmQnc
} I+,~pmn:
} S`oADy
if(breakWhile) 9Ij=~p]p
break; j~(s3pSCo
4!pMZ<$3
*OOi
//count++; 0j^QY6
//if(count>4) wN"j:G(
// siteStop(); I%]~]a
} g\CRx^s
3BuG_ild
`ZCeuOH
System.err.println("文件下载结束！"); '?Mt*%J@=$
} "@1e0`n Q
catch(Exception e){e.printStackTrace ();} x;&01@m.
} 9`P<|(
:Ve>tZeW
:+%"kgJNL
//获得文件长度 !_Z\K$Ns
public long getFileSize() F?UI8
{ -nVQB146^
int nFileLength = -1; aDrF"j
try{ #wXq'yi
URL url = new URL(siteInfoBean.getSSiteURL()); !~+"TI}_%w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B$R"Ntp
httpConnection.setRequestProperty("User-Agent","NetFox"); )-D{]>8
< Y5pAStg
ldd|"[Ds
int responseCode=httpConnection.getResponseCode(); E8_j?X1
if(responseCode>=400) P9Yee!*H
{ ({XB,Rm
processErrorCode(responseCode); x=1Iuc;&3
return -2; //-2 represent access is error f{ ;L"*L
} 4+rr3 $AY
en6Kdqe
ZY_aE
String sHeader; -&N^S?
_[D6WY+
?T]` X
for(int i=1;;i++) 05 P#gs`<
{ Z>0a?=1[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z~&$s
//Utility.log(in.readLine()); N_3$B=
sHeader=httpConnection.getHeaderFieldKey(i); W6~aL\[
if(sHeader!=null) 1r!o,0!d-'
{ W9i}w&
if(sHeader.equals("Content-Length")) e"^ /xF
{ 5k%GjT
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1~J:hjKQ
break; "H{Etb/
} OV@MT^
} MHl ffj
else MR=dQc
break; |p4D!M+$7
} 6wIo95`
} Uq}FrK}
catch(IOException e){e.printStackTrace ();} QCm93YZs6E
catch(Exception e){e.printStackTrace ();} A_h|f5
F0.Rv):
HuVx^y` @
Utility.log(nFileLength); *Sd}cDCO%
x9QUo*MT
SRU}-
return nFileLength; a ~
} w^{qut.
,,FO6+4f
Ch] `@(l
//保存下载信息（文件指针位置） bD2):U*Fzo
private void write_nPos() xE$>;30b_
{ B//2R)HS
try{ <\44%M"iC-
output = new DataOutputStream(new FileOutputStream(tmpFile)); `;`fA|F^
output.writeInt(nStartPos.length); M%yeI{m
for(int i=0;i<nStartPos.length;i++) OON]E3yy
{ 0A,u!"4[
// output.writeLong(nPos); Jw+k=>
output.writeLong(fileSplitterFetch.nStartPos); [Re.sX}$Y
output.writeLong(fileSplitterFetch.nEndPos); !t;B.[U *
} sYfiC`9SO
output.close(); *#n#J[
} bjL8Wpk
catch(IOException e){e.printStackTrace ();} %%-?~rjI
catch(Exception e){e.printStackTrace ();} 3rxB]-
} T{CCZ"Fv
q PveG1+25
T^Lg+g+I
//读取保存的下载信息（文件指针位置） OMY^'g%w
private void read_nPos() ln1QY"g
{ 'K!u}py
try{ pdw;SIoC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o8RVmOXe
int nCount = input.readInt(); (kYwD
nStartPos = new long[nCount]; J4) ?hS
nEndPos = new long[nCount]; )yTBtYw3
for(int i=0;i<nStartPos.length;i++) *3!#W|#=]N
{ 2Wx~+@1y
nStartPos = input.readLong(); x/d(" Bb
nEndPos = input.readLong(); srGF=1_
} 7l+:gD
input.close(); WV8vDv1jt
} `Eg~;E:
catch(IOException e){e.printStackTrace ();} b(HbwOt~3
catch(Exception e){e.printStackTrace ();} v =]!Po&Q-
} "y7IH GJ\3
]aZ3_<b
}m -A #4.
private void processErrorCode(int nErrorCode) fG,)`[eD!_
{ olxnQYFo
System.err.println("Error Code : " + nErrorCode); 6JB*brO
} "*T4%3dA
lJJ`aYDp
(:|rCZC
//停止文件下载 Q/%]%d
public void siteStop() K/l*Saj
{ @c-| Sl
bStop = true; 6k6}SlN[
for(int i=0;i<nStartPos.length;i++) BCI[jfd7
fileSplitterFetch.splitterStop(); B1k;!@@14
h|{DIG3
PLueH/gC.
} MC~<jJ,
} v\G+t2{
//负责部分文件的抓取 wv.HPmq
**FileSplitterFetch.java 2u%YRrp
*/ (7A-cC
package NetFox; M`49ydh&
*%n(t+'q
hkDew0k
import java.io.*; ^US ol/
import java.net.*; Ve[[J"ze
^u+#x2$Mg
aflBDo1c
public class FileSplitterFetch extends Thread { 7U2?in}?Qi
ZkmYpi[
0]Qk*u<
String sURL; //File URL h1+y.4
long nStartPos; //File Snippet Start Position ly::?
long nEndPos; //File Snippet End Position D}OhmOu3
int nThreadID; //Thread's ID hH~GH'dnaE
boolean bDownOver = false; //Downing is over %fIYWu`X
boolean bStop = false; //Stop identical kLe{3>}j
FileAccessI fileAccessI = null; //File Access interface vEc<|t
|lMc6C
^ pNA_s!S
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #]*]qdQWV^
{ }q=tg9
this.sURL = sURL; )S^[b2P]y_
this.nStartPos = nStart; Vtv1{/@+c
this.nEndPos = nEnd; v!j%<H`NI
nThreadID = id; i$6o>V6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 srryVqgS
} $ qTv2)W1{
X}Fqif4A
qZ%0p*P#_
public void run() &HtG&RvQf
{ P-\65]`C
while(nStartPos < nEndPos && !bStop) "eIE5h
{ Ao, <G.>R
Rnw v/)
3/Dis) v8
try{ (s,u9vj=>L
URL url = new URL(sURL); df{6!}/(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q{XeRQ'/
httpConnection.setRequestProperty("User-Agent","NetFox"); 7X8n|NZRH7
String sProperty = "bytes="+nStartPos+"-"; BeFXC5-qat
httpConnection.setRequestProperty("RANGE",sProperty); 'H(khS
Utility.log(sProperty); +&[X7r<
Uy<n7*H
-/R?D1kOq
InputStream input = httpConnection.getInputStream(); Q6r7UM
//logResponseHead(httpConnection); %FJB9?9=|
iCy$ rC
#]J"j]L
byte[] b = new byte[1024]; <f;Xs(
int nRead; EMf"rGXu(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p:xVi0
{ Ebp=du
nStartPos += fileAccessI.write(b,0,nRead); o`.5NUn
//if(nThreadID == 1) vk<4P;A(G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PoZxT-U
} g2 tM!IRQ
!H(V%B%
)D"2Q:
Utility.log("Thread " + nThreadID + " is over!"); %t%D|cf
bDownOver = true; 8@]vvZ2/gj
//nPos = fileAccessI.write (b,0,nRead); P9M. J^<
} U98e=57N
catch(Exception e){e.printStackTrace ();} Qb@i_SX(fs
} AQ)J|i
} 9:7&`JlC#
i!+0''i{#
W_[ tdqey
//打印回应的头信息 "]B%V!@
public void logResponseHead(HttpURLConnection con) S'=}eeG
{ w\ddC DZ
for(int i=1;;i++) {YEGy
{ -EG=}uT['b
String header=con.getHeaderFieldKey(i); g5t`YcL
if(header!=null) j`%a2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HAAU2A9B2
Utility.log(header+" : "+con.getHeaderField(header)); 8UXtIuQ
else < mp_[-c
break; [#;CBs5o
} u_6x{",5I
} okH*2F(-
Zo@
ITfz/d8
public void splitterStop() ~c@@m\C"b
{ H4uHCkj
bStop = true; ZC3;QKw>
} sZ#U{LI
@gk{wh>c
n"f:6|<
} QZFH>,d
T}K@ykT
iIc/%< ;
/* yo :63CPP
**FileAccess.java sv2XD}}
*//文件访问(定位，写) ]r>m{"~E
package NetFox; 0D&-BAzi
import java.io.*; b&*N
a'?V:3 ]
64t:
public class FileAccessI implements Serializable{ &p5^Cjy L
7myYs7N8[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VCa`|S?2
RandomAccessFile oSavedFile; :\~YbA
long nPos; .yQ<
\2M{R
/]9(InM9/
public FileAccessI() throws IOException c6tH'oV
{ zh9B8r)C
this("",0); a2B9 .;F
} X08[,P#I
L@`:mK+;
lCGEd 3
public FileAccessI(String sName,long nPos) throws IOException smHQ'4x9
{ >)VWXv0
oSavedFile = new RandomAccessFile(sName,"rw"); p']{WLDj2
this.nPos = nPos; 7AQv4
oSavedFile.seek(nPos); Z5,"KhB]
} *|6*jU
Yduj3Ht:w
s,-}}6WO
public synchronized int write(byte[] b,int nStart,int nLen) 4{LKT^(!f
{ lfqsoIn;
int n = -1; $'COsiK7
try{ 9b)'vr*Hy7
oSavedFile.write(b,nStart,nLen); {0L)B{|
n = nLen; p/KG{-f,
} F{laA YE
catch(IOException e) 76b2 3|
{ aMaqlqf
e.printStackTrace (); e5m]mzF@
} h`4!Qv
3W}qNY;J
^_k`@SU
return n; Nzl`mx16
} q0(-"}2l
nKe|xP
Iy Vmz'
} 1HUe8m[#3
g&X X@I8+v
ja^
/* Nl9}*3r
**SiteInfoBean.java 0xUn#&A~
*/ na3lbwq
package NetFox; RM#.-gW
Wo6C0Z3g}
Xvxj-\ -
public class SiteInfoBean { =:m6ge@C&H
pPJE.[)V/
p)s*Cw
private String sSiteURL; //Site's URL @Op7OFY%
private String sFilePath; //Saved File's Path Pl&x6\zL
private String sFileName; //Saved File's Name u>[hLXuB
private int nSplitter; //Count of Splited Downloading File a6hDw'8!
lSBu,UQP
hlFvm$P`M
public SiteInfoBean() nS]Ih0(K
{//nSplitter的缺省值为5 [y(<1]i-a
//default value of nSplitter is 5 Z=^~]Mfa
this("","","",5); 7$"n.cr :
} wa$Q8/
'v%v*Ujf[
gFr-P!3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ij02J`w:Ra
{ .{"wliC2
sSiteURL= sURL; ||'A9
sFilePath = sPath; <+AvbqDe
sFileName = sName; i:x<Vi
this.nSplitter = nSpiltter; Og2G0sWRf
Nj+gSa9
)uy2,`z
} AIt;~x
#* Iyvx
BZk0B?
public String getSSiteURL() /v7o!D1G
{ %!OA/7XbG
return sSiteURL; +%)bd
} b.QL\$a &
@c;:D`\p1C
Bu7aeBP
public void setSSiteURL(String value) }/aqh;W
{ ?J28@rM
sSiteURL = value; .CEl{fofj
} SD]rYIu+
C |P(,Xp
(RI+4V1
public String getSFilePath() *iXaQuT
{ ;f9a0Vs
return sFilePath; SH;:bLk_
} FXFyF*w2
b:W x[+
Wrs6t
public void setSFilePath(String value) dWVm'd
{ !.[H!-V.
sFilePath = value; R;H>#caJ
} mC./,a[
@hOT< Uo
Z^%aXaf8
public String getSFileName() g!!:o(k
{ 58gkE94
return sFileName; "1ov<
} \OK"r-IO
#oxP,LR
<E\vc6n
public void setSFileName(String value) MbyV_A`r_
{ "~6IjW*/
sFileName = value; HKG8X="
} UiH5iZ<r;
\>c1Z5H>
4x?4[J~u[
public int getNSplitter() FUs57 V
{ koy0A/\%
return nSplitter; </23*n]
} H<ZXe!q(nx
Nuc2CB)J
c<imqDf
public void setNSplitter(int nCount) {h~<!sEX
{ /R[PsB
nSplitter = nCount; @+; cFj
} 17yg ~
} KBwY _
*DPKV$
T)*tCp]
/* Jp +h''t
**Utility.java 15"[MX A
*/ HC(o;,spO
package NetFox; (zIF2qY
/[>zFYaQ
&ej|DM6
public class Utility { [G7S
BaOPtBYA:
-ei+r#
public Utility() vz`r !xj)
{ p@%H. 5&&
,<<HkEMS
?D=t:=
} W>m#Mz
gbN@EJ
//线程睡眠 j$=MJN0
public static void sleep(int nSecond) bh UghHT
{ T*zy^we
try{ -SKcS#IF
Thread.sleep(nSecond); f}{Oj-:"CC
} },vVc/
catch(Exception e) <O9.GHV1v
{ KAm$^N5
e.printStackTrace (); H?)?(t7@
} @po|07
} UjH+BC+9`b
8M7pc{
//日志 =pn(56
public static void log(String sMsg) 7K &j
{ e7JZk6GP#9
System.err.println(sMsg); bTc'E#
} ^li(q]g1!
DK }1T
=\)qUs\z
public static void log(int sMsg) +y|H#(wBP
{ I>45xVA
System.err.println(sMsg); i0*6o3h
} p$bR M`R&s
} If%**o
)}5f'TK
&*!) d"
/* )GF>]|CG
**TestMethod.java ~OOD#/
*/ (vr v-4
package NetFox; aOTrng
\%/zf
-'Y@yIb
public class TestMethod { s14;\
L+d4&x
iV8O<en&i
public TestMethod() qlIbnyP<
{ ///xx/weblogic60b2_win.exe +*P;Vb6D
try{ 3hbUus
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `=rDB7!$yL
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y/yg-\/XF
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,?Nc\Q<:
fileFetch.start(); a0[Mx 4
} </7_T<He.
catch(Exception e){e.printStackTrace ();} g;PZ$|%&s>
!L\P.FP7b
R.B3
} $Y31YA
F~${L+^
R7-+@
public static void main(String[] args) ;,F:.<P
{ 0xe*\CAo
new TestMethod(); TWAt)Q"J
} `#w`-
} 3tIno!|
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