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)); K[G=J
} rO;Vr},3\%
for(int i=0;i<nEndPos.length-1;i++) .~L^h/)Gjy
{ 'UN 'gXny
nEndPos = nStartPos[i+1]; c1CUG1i
} +o*&JoC
nEndPos[nEndPos.length-1] = nFileLength; [$+N"4
} :"utFBO
} YS|Ve*t(L=
-$0w-M8'
ta)'z@V@g
//启动子线程 !}$,) ~<+H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oDvE0"Sz
for(int i=0;i<nStartPos.length;i++) PRpW*#"EI
{ So^;5tG
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :~gG]|F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E5EAk6
nStartPos,nEndPos,i); q n2X._`
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8`?vWJS
fileSplitterFetch.start(); `~S; UG
} Dg_AoC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %Q2<bj]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iAWd 9x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", __Tg1A
nEndPos = " + nFileLength); PL6f**{-
// fileSplitterFetch[nPos.length-1].start(); ~ v21b?
=Kh1HU.F
y"o@?bny
//等待子线程结束 FJYc*l
//int count = 0; *|F ;An.N^
//是否结束while循环 ~Y3"vdd
boolean breakWhile = false; "7RnT3
.V.x0
8G6[\P3fQ
while(!bStop) 2TxHY|4
{ }-8ZSWog6f
write_nPos(); WXgGB[x
Utility.sleep(500); {YoK63b$
breakWhile = true; q=+AN</
M6mJ'Q482
ZY Ci&l
for(int i=0;i<nStartPos.length;i++) W.O]f.h
{ fkjo
if(!fileSplitterFetch.bDownOver) *>%tx k:)
{ O,+ZD^
breakWhile = false; ?~_[/
break; }wkZ\q[
} @$bEY#*C
} ,^#{k!uaC{
if(breakWhile) 74u_YA<"
break; )kl(}.9X
sBuOKT/j
&qO#EEqG]
//count++; *53@%9 {u
//if(count>4) /ivA[LSS
// siteStop(); "N\tR[P!
} o(5eb;"yi>
y))) {X
BWHH:cX
System.err.println("文件下载结束！"); TTSyDl
} 1[&V6=n
catch(Exception e){e.printStackTrace ();} }kK6"]Tj
} `[=3_
]3/_?n-"`
zP(UaSXz/
//获得文件长度 d2!A32m
public long getFileSize() hfBZ:es+
{ XX:?7:j}[8
int nFileLength = -1; f'>270pH
try{ [Jjb<6[o
URL url = new URL(siteInfoBean.getSSiteURL()); ~s[St0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /l)|B
httpConnection.setRequestProperty("User-Agent","NetFox"); pm 4"Q!K
c%bGVRhE
;vDjd2@
int responseCode=httpConnection.getResponseCode(); i4XE26B;e
if(responseCode>=400) 4EZl (v"f`
{ )8rN
processErrorCode(responseCode); A/%+AH(
return -2; //-2 represent access is error )PNeJf|@
} q#n0!5Lv2
0M=U>g)
M'"@l$[QM
String sHeader; fZH";_"1
k-`5TmW
ZI0C%c.~
for(int i=1;;i++) t;?TXAA
{ f L}3I(VK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IB sQaxt.
//Utility.log(in.readLine()); <:tD m
sHeader=httpConnection.getHeaderFieldKey(i); e/{1u$
if(sHeader!=null) ^q$m>|KI
{ hA0g'X2eC
if(sHeader.equals("Content-Length")) ha%3%O8Z
{ mK>c+ u)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); _?+gfi+
break; 4 )U,A~!
} 0bt"U=x4
} T/$6ov+K
else k^vsQ'TD
break; h ?Ni5
} IQ`#M~:
} "0&+`7
catch(IOException e){e.printStackTrace ();} X9YYUnR2
catch(Exception e){e.printStackTrace ();} r@XH=[:
_eE hIQ9
z'(][SB
Utility.log(nFileLength); J!5>8I(_wX
)0Lno|l
^Iz(V2
return nFileLength; x2KIGG^
} ;Rz+4<
b\dzB\,&
etPb^&#$
//保存下载信息（文件指针位置） }!W,/=z*
private void write_nPos() F_?aoP&5
{ @ z{E
try{ 20O\@}2q2M
output = new DataOutputStream(new FileOutputStream(tmpFile)); n'&Cr0{
output.writeInt(nStartPos.length); ~`<(T)rs
for(int i=0;i<nStartPos.length;i++) 6;:s N8M+1
{ C_RxJWka
// output.writeLong(nPos); **%/Ke[
output.writeLong(fileSplitterFetch.nStartPos); k6pXc<]8
output.writeLong(fileSplitterFetch.nEndPos); 5c W2
} "i}?jf {a
output.close(); !5/jDvh
} Q|O! cEW/
catch(IOException e){e.printStackTrace ();} |Zn|?#F
catch(Exception e){e.printStackTrace ();} 9qHbV 9,M
} [KT'aGK$
"8'aZ.P
%s^2m"ca}=
//读取保存的下载信息（文件指针位置） ]4$t'wI.
private void read_nPos() !@r1B`]j+"
{ ?0{8fGM4
try{ NJVAvq2E.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RwG@C|sG
int nCount = input.readInt(); h{R>L s
nStartPos = new long[nCount]; #K5)Rb-H
nEndPos = new long[nCount]; }=+J&cR
for(int i=0;i<nStartPos.length;i++) P{'T9U|O-
{ (}E ] g
nStartPos = input.readLong(); 0&YW#L|J
nEndPos = input.readLong(); ^Ia:e ?)W
} 3Pj 6(cf
input.close(); A`NkgVq5:
} u Z(vf
catch(IOException e){e.printStackTrace ();} rfl-(_3
catch(Exception e){e.printStackTrace ();} s Y^#I
} f:=y)+@1My
OF4iGFw
;{zgp
private void processErrorCode(int nErrorCode) O e-FI+7
{ Nan@SuKY
System.err.println("Error Code : " + nErrorCode); %`kO\q_
} E*uz|w3S)Y
x}8 U\
Jvk!a~e
//停止文件下载 DvBL#iC
public void siteStop() dK5|tWJX
{ Q :<&<i=I
bStop = true; ^UB<U#8,
for(int i=0;i<nStartPos.length;i++) vp"b_x1-
fileSplitterFetch.splitterStop(); AB!P(
epcBr_}
wVSk.OOB
} DRo?7_
} "M)kV5v%
//负责部分文件的抓取 y@5{.jsr_
**FileSplitterFetch.java .d^XM
*/ 6@"lIKeP
package NetFox; GE2^v_
]dx6E6A,
yJ\K\\]
import java.io.*; *?'^Rc
import java.net.*; yX%Xjo__*t
!`3q9RT3."
l"I G;qO.
public class FileSplitterFetch extends Thread { yXuF<+CJ
MDHTZ94\Q
|KV|x^fJ
String sURL; //File URL /M}jF*5N
long nStartPos; //File Snippet Start Position 69z,_p$@:
long nEndPos; //File Snippet End Position zdL"PF
int nThreadID; //Thread's ID #6'x-Z_
boolean bDownOver = false; //Downing is over Nq$Xe~,*
boolean bStop = false; //Stop identical q_h=O1W
FileAccessI fileAccessI = null; //File Access interface +A 4};]W|
@w%{yzr%
6AM-^S@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =B0#z]qu
{ -HE@wda
this.sURL = sURL; ^ #6Ei9di
this.nStartPos = nStart; -^Pn4y]A)
this.nEndPos = nEnd; k>2tC<
nThreadID = id; =JqKdLH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tX<. Ud
} 2MV!@rx
XLog+F$`
%^5|3l3y
public void run() sPu@t&$
{ TA2?Ia;@xV
while(nStartPos < nEndPos && !bStop) t_VF=B^LuR
{ _(qU%B
!|G 8b'
&jg..R
try{ =i`#0i2(
URL url = new URL(sURL); 'b?Px}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (M>[D!Yt
httpConnection.setRequestProperty("User-Agent","NetFox"); i`FskEoijq
String sProperty = "bytes="+nStartPos+"-"; 4Ou|4WjnL
httpConnection.setRequestProperty("RANGE",sProperty); 0R#T3K}
Utility.log(sProperty); I;Sg9`k=
cZ<@1I5QK
D2060ze
InputStream input = httpConnection.getInputStream(); F2B9Q_>P
//logResponseHead(httpConnection); g RX`61
1x"S^j
I6q]bQ="
byte[] b = new byte[1024]; (jV_L1D
int nRead; "@!B"'xg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o 0-3[W'x<
{ Cwb}$=p'
nStartPos += fileAccessI.write(b,0,nRead); )kBN]>&R
//if(nThreadID == 1) {JJq/[j
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -Um|:[*I
} \Q CH.~]
<b5J"i&m
4v=NmO}
Utility.log("Thread " + nThreadID + " is over!"); \Y>!vh X
bDownOver = true; -W#-m'Lvu
//nPos = fileAccessI.write (b,0,nRead); 'Q^P#<<
} l2AAEB_C.
catch(Exception e){e.printStackTrace ();} e=8z,.Xk
} &fyT}MA
} K}r@O"6*\
|i}5vT78
_ ?\4k{ET
//打印回应的头信息 O%>FKU>(?
public void logResponseHead(HttpURLConnection con) rA"><pH
{ PB W.nm
for(int i=1;;i++) B9Ha6kj
{ }'"4q
String header=con.getHeaderFieldKey(i); #dd-rooQuD
if(header!=null) Ykt{]#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5S;|U&f|
Utility.log(header+" : "+con.getHeaderField(header)); H.n+CR
else cAL*Md8+
break; "TLY:V
} n#NE.ap$&,
} SWrt4G
,X&(BQj h
.y)Y20=o!
public void splitterStop() snl$v
{ voD0u
bStop = true; >h[ {_+
} MPn 6sf9M
$69ef[b
|?kZfr&9q
} miq"3
W@T_-pTCjK
ThvVLK
/* e%B;8)7
**FileAccess.java ~&UfnO
*//文件访问(定位，写) ZjOUk;H?
package NetFox; `;:zZ8*
import java.io.*; B?-~f^*,jG
a2z1/Nh
-kv'C6gB
public class FileAccessI implements Serializable{ Me.t_)
+FYQ7UE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bsn.HT"5
RandomAccessFile oSavedFile; ,pg\5b
long nPos; Uc?4!{$X
JyfWy
d{gj8
public FileAccessI() throws IOException ~<)CI0=
{ >_<J=8|E
this("",0); iJr 1w&GL$
} GOzV#
NY& |:F
=s\RK
public FileAccessI(String sName,long nPos) throws IOException v4YY6?4
{ kJOSGrg
oSavedFile = new RandomAccessFile(sName,"rw"); 5W(S~}
this.nPos = nPos; ToNRY<!
oSavedFile.seek(nPos); h|DKD.
} RyJN=;5p
PN +<C7/
fV\ eksBF
public synchronized int write(byte[] b,int nStart,int nLen) L, k\`9bQ
{ gLH#UwfJ
int n = -1; qXb{A*J
try{ HoFFce7o
oSavedFile.write(b,nStart,nLen); ]rhxB4*1
n = nLen; og! d
} B F,rZZL
catch(IOException e) cl4Vi%
{ VgoN=S
e.printStackTrace (); TsX(=N_
} o C5}[cYD`
R>3a?.X
"]"!"#aMv
return n; !GNLq.rQ
} "(U%Vg|)
!aVwmd'9
l5 FM>q
} Je5UVf3>2&
+yh-HYo`
E@f2hW2
/* ;M95A
**SiteInfoBean.java CXzN4!
*/ w'Cn3b)`
package NetFox; 5T,In+~Kd
P/'9k0zs)
-d|VXD5N
public class SiteInfoBean { "n4' \ig
N~w4|q!]
Fp`MX>F
private String sSiteURL; //Site's URL bc".R]
private String sFilePath; //Saved File's Path @`</Z)
private String sFileName; //Saved File's Name U;QN+fF]u
private int nSplitter; //Count of Splited Downloading File #kuk3}&
<MPoDf?h
)bM #s">Y
public SiteInfoBean() @rTAbEk{U
{//nSplitter的缺省值为5 @\!9dK-W
//default value of nSplitter is 5 icX$<lD
this("","","",5); 6L2Si4OGjG
} Ww }qK|D
\[-z4Fxg|'
LEUD6 M+~t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !*U#,qY
{ >-~2:d\M3
sSiteURL= sURL; 0B4&!J
sFilePath = sPath; `$X|VAS2
sFileName = sName; 8@S5P$b};
this.nSplitter = nSpiltter; xSQ0]vE
5&uS700
C&\vVNV;9
} D-/aS5wM
OfR\8hAY
e' `xU
public String getSSiteURL() d^&F%)AT
{ $S"QyAH~-a
return sSiteURL; Vs)%*1><
} f>u{e~Q,
7Y8B \B)w
+dkbt%7M
public void setSSiteURL(String value) )BuS'oB
{ $rZ:$d.C
sSiteURL = value; 4zF|}aiQ
} Wgh4DhAW
#&@qmps(T
:\0q\2e[<
public String getSFilePath() Se o3a6o
{ +3c!.] o;
return sFilePath; x bG'![OX
} wGqQR)a
_t:l:x.;T
&zCqF=/9U
public void setSFilePath(String value) $Qm-p?f
{ KAR XC,z
sFilePath = value; ~dIb>[7wy
} (okCZ-_Jn
fs]9HK/@\
,tEvz
public String getSFileName() !n=@(bT*wT
{ brQkVt_)EE
return sFileName; cI)XXb4
} >!j= {hK
W~1/vJ.*l
m_%1IJ
public void setSFileName(String value) $RQ7rL3g{
{ 5(/ 5$u
sFileName = value; @G vDl=.
} G-U%
|~! R5|Q
CS 7"mE`{
public int getNSplitter() s*gyk
{ {__Z\D2I
return nSplitter; _v=@MOI/J
} \WM*2&
#5?Q{ORN o
;Yrg4/Ipa
public void setNSplitter(int nCount) Mk=;UBb$X
{ TQ?D*&
nSplitter = nCount; H=vrF-#
} DPfP)J:~
} nL}bCX{
mT.p-C
IJ^KYho
/* }2Lh'0 xY
**Utility.java )x.}B4z
*/ _tR%7%3*
package NetFox; U.oxLbJ`
(~oUd4
]fXMp*LvY
public class Utility { rK*s/mX <
%Fc,$ =
hFw\uETu
public Utility() _nR8L`l*z
{ TEZ^Ia
khl(9R4a
/Yk2 |L
} Kp*nOZ
L~1u?-zu
//线程睡眠 >4a@rT/
public static void sleep(int nSecond) .>0e?A4,5?
{ "(}xIsy
try{ N\<RQtDg
Thread.sleep(nSecond); [y y D-
} Vw*;xek?
catch(Exception e) ce{GpmW
{ 4BG6C'`%
e.printStackTrace (); L<>;E
} tb7Wr1$<
} #Zpp*S55
(Rvke!"B
//日志 Wh%qvV6]
public static void log(String sMsg) w,NK]<dU@
{ bz_Zk
System.err.println(sMsg); pb`F_->uq
} ?;.j)
V *=To
X75>C<
public static void log(int sMsg) uROt h_/
{ - Z"w
System.err.println(sMsg); oC>QJ(o,8
} =:aH2T*
} eL9RrSXz
Q3#-q>;7
@oC8:
/* h0NM5
**TestMethod.java o#{D;'
*/ ;$@7iL
package NetFox; u~yJFIo
|KF X0*70
'v4#mf
public class TestMethod { OiX>^_iDt
$}<+~JpGfP
1oaiA/bq
public TestMethod() 1TfK"\
{ ///xx/weblogic60b2_win.exe hS&,Gm`^
try{ L)VEA8}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~$>l@> xX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y3$i?}?A
SiteFileFetch fileFetch = new SiteFileFetch(bean); :W,6zv(..u
fileFetch.start(); M#on-[
} qUSImgg
catch(Exception e){e.printStackTrace ();} v$"#9oh
V\@h<%{^%7
4EzmH)4G
} #M6@{R2_
o)'T#uK
EA%(+tJ^0
public static void main(String[] args) E;~gQ6vAI
{ Qvs}{h/
new TestMethod(); ,+P!R0PNH
} o=?sMq1<
} OA2<jrGB!
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