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)); aD^jlt
} ^(kmFUV,Z
for(int i=0;i<nEndPos.length-1;i++) w#v-h3XcF
{ }j$tFFVi~
nEndPos = nStartPos[i+1]; MgO_gFr
} < ]"Uy p
nEndPos[nEndPos.length-1] = nFileLength; p[Zk;AT~
} 3AcS$.G
} Rp+Lu
?;]Xc~
,(i`gH{D
//启动子线程 q2b>Z6!5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8vkCmV
for(int i=0;i<nStartPos.length;i++) >,x&L[3
{ 'yo-`nNFD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $^e(?Pq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WA6reZ
nStartPos,nEndPos,i); P5KpFL`B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '4Drs}j5
fileSplitterFetch.start(); P3!JA)p6a
} `pb=y}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), D\^mh{q(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `]`S"W7&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H Y~[/H+:
nEndPos = " + nFileLength); -zg 6^f_pW
// fileSplitterFetch[nPos.length-1].start(); iNs@8<=$T
f AY(ro9Q(
(gRTSd T?
//等待子线程结束 mEmgr(W
//int count = 0; Cxd^i
//是否结束while循环 h,\5C/
boolean breakWhile = false; aX,6y1
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5O(U1 *
while(!bStop) %I=/ y
{ wRdN(`;v
write_nPos(); EK.n $
Utility.sleep(500); EfB.K}b^
breakWhile = true; !hFzIp
qZdA%
j[Jwa*GQP
for(int i=0;i<nStartPos.length;i++) :HM~!7e
{ .6!cHL3ln
if(!fileSplitterFetch.bDownOver) bt*
{ o@m7@$7
breakWhile = false; !K-qoBqKM
break; X$Shi *U[
} N\"Hf=Y(~
} mBxMDnh
if(breakWhile) =Fc}T%
break; q[Tl#*P?y
:-_"[:t 5Z
-_xTs(;|8
//count++; SP\s{,'F-b
//if(count>4) ;VzdlCZ@
// siteStop(); wh#IQ.E-
} I<Cm$8O?
9n49p?
GkxQEL
System.err.println("文件下载结束！"); "Lyb4#M
} PWeWz(]0Z4
catch(Exception e){e.printStackTrace ();} j u&v4]
} <*I*#WI&B
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bk0<i*ju7(
//获得文件长度 r $[{sW
public long getFileSize() iGSF5S
{ Es- =0gpK
int nFileLength = -1; vmv6y*qU
try{ 0 .UN
URL url = new URL(siteInfoBean.getSSiteURL()); baBPf{<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q;ZV`D/FA
httpConnection.setRequestProperty("User-Agent","NetFox"); e7y,zcbv
SQ*%d.1
c'XSs
int responseCode=httpConnection.getResponseCode(); xU2i&il^!
if(responseCode>=400) Jz4;7/
{ odDVdVx0
processErrorCode(responseCode); 8>G5VhCm~o
return -2; //-2 represent access is error ex#-,;T
} <`WDNi$Y
l9]nrT1Hy
V$wbmz
String sHeader; g:.LCF
^I9U<iNIL
^F qs,^~W
for(int i=1;;i++) \PD%=~
{ ?VCp_Ji
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @HTs.4
//Utility.log(in.readLine()); /eT9W[a
sHeader=httpConnection.getHeaderFieldKey(i); ]heVR&bQ
if(sHeader!=null) xi=0kO
{ vT MCZ+^g
if(sHeader.equals("Content-Length")) OLWn0
{ S(Z\h_m(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :fDzMD
break; q6hH]Q>w*
} U# IPYyV
} v-8{mK`9\
else ([|^3tM
break; LN)yQ-
} ~c55LlO>
} ~Y{]yBGoF
catch(IOException e){e.printStackTrace ();} Lr20xm
catch(Exception e){e.printStackTrace ();} 8QMMKOui\
<Qr*!-Kc6
elR1NhB|p
Utility.log(nFileLength); -]-0]*oAp
&> _aY #
j+>[~c;0)
return nFileLength; 9ei<ou_s
} c(29JZ
I %sw(uoE
"$b{EYq6
//保存下载信息（文件指针位置） N A_8<B^
private void write_nPos() c6 .j$6t
{ Zl>wWJ3y
try{ -GCU6U|
output = new DataOutputStream(new FileOutputStream(tmpFile)); R5mb4
output.writeInt(nStartPos.length); V6+:g=@U-l
for(int i=0;i<nStartPos.length;i++) 4jlwu0L+
{ BpGyjoJ2
// output.writeLong(nPos); tk)}4b^\%j
output.writeLong(fileSplitterFetch.nStartPos); V3T.EW
output.writeLong(fileSplitterFetch.nEndPos); h#Mx(q
} C?MKbD=K
output.close(); zlB[Eg^X
} v9!]/]U^
catch(IOException e){e.printStackTrace ();} *>!-t
catch(Exception e){e.printStackTrace ();} 8Ht=B,7T
} J*zQ8\f=}
uhv_'Q
Z"KrirZ
//读取保存的下载信息（文件指针位置） :^qUr`)
private void read_nPos() tR4+]K
{ >p#_L^oZ%
try{ OlptO60{ ]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D+N@l"U{
int nCount = input.readInt(); _RS CyV
nStartPos = new long[nCount]; fGW~xul_
nEndPos = new long[nCount]; Ic^ (6
for(int i=0;i<nStartPos.length;i++) .Wi%V"
{ [w-# !X2y
nStartPos = input.readLong(); ?!$Dr0r
nEndPos = input.readLong(); 0'Qvis[kt
} !s !el;G
input.close(); @*uZ+$
} Z^Wv(:Nr
catch(IOException e){e.printStackTrace ();} ]zj&U#{
catch(Exception e){e.printStackTrace ();} FW)~e*@8=
} {d0 rUHP
I)9,
VV#'d
private void processErrorCode(int nErrorCode) #)i+'L8
{ ' QjJ^3A
System.err.println("Error Code : " + nErrorCode); #s#BYbF
} *5\'$;Rg
B/mfm 7
~0o>B$xJ
//停止文件下载 IFZw54
public void siteStop() 56u_viZ=8
{ ~9,Fc6w4`+
bStop = true; sHV?njZd
for(int i=0;i<nStartPos.length;i++) loHMQKy@
fileSplitterFetch.splitterStop(); \4 +HNy3
`,Y3(=3Xe?
90-s@a3B-j
} R:ecLbC
} knfmJUT
//负责部分文件的抓取 JV8*;n%}-
**FileSplitterFetch.java g&Uu~;jq]
*/ g $^Yv4
package NetFox; )cL`$h4DD
8A/rkoht*
^4p$@5zH
import java.io.*; " YOl6n
import java.net.*; U7e2NES
'Q=(1a11
b/\l\\$-
public class FileSplitterFetch extends Thread { U'~]^F%eyu
m( %PZ*s
(/9erfuJ
String sURL; //File URL J/,m'wH
long nStartPos; //File Snippet Start Position I>6zX
long nEndPos; //File Snippet End Position I47sqz7
int nThreadID; //Thread's ID 5^CWF|
boolean bDownOver = false; //Downing is over gR_Exs'K
boolean bStop = false; //Stop identical w'y,$gtX/
FileAccessI fileAccessI = null; //File Access interface k!x`cp
aWP9i&
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException <(xro/
{ 'F:Tv[qx
this.sURL = sURL; gNkBHwv
this.nStartPos = nStart; w4&\-S#
this.nEndPos = nEnd; b`}hw"f
nThreadID = id; Z Y5Pf 1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !t{
} JW=q'ibR
pX$X8z%
"`4M4`'
public void run() ,% .)mf
{ v`Ja Bn
while(nStartPos < nEndPos && !bStop) ^X"x,8}&V
{ A!uiM*"W
I*g[Y=
/YvwQ
try{ Adfnd
URL url = new URL(sURL); *Uf>Xr&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;E!] /oY<
httpConnection.setRequestProperty("User-Agent","NetFox"); YM.
String sProperty = "bytes="+nStartPos+"-"; G c,
httpConnection.setRequestProperty("RANGE",sProperty); aN6HO
Utility.log(sProperty); :o~]d
SP>&+5AydX
N-Bw&hEZ
InputStream input = httpConnection.getInputStream(); )wdd"*hv
//logResponseHead(httpConnection); 5)0'$Xxqa0
|0X~D}r|J
!\OX}kHX5
byte[] b = new byte[1024]; *_HF%JYMZ
int nRead; # $'H?lO
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) QBfo=9[=e
{ /#q6.du
nStartPos += fileAccessI.write(b,0,nRead); FJ{&R Ld
//if(nThreadID == 1) hx4c`fOs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X+N8r^&
} k@gQY_
LW9F%?e!>
&]A0=h2{P*
Utility.log("Thread " + nThreadID + " is over!"); qagR?)N)u
bDownOver = true; ]mC5Z6,1s
//nPos = fileAccessI.write (b,0,nRead); >McEuoZx9
} 5dbj{r)s6i
catch(Exception e){e.printStackTrace ();} ov >5+"q)
} K*p3#iB
} 3BF3$_u)o
CAN1~
`joyHKZI.
//打印回应的头信息 Wdga(8t
public void logResponseHead(HttpURLConnection con) b dC
{ 8,e%=7h_e
for(int i=1;;i++) dOKe}?}==
{ Q|U [|U
String header=con.getHeaderFieldKey(i); kQn}lD
if(header!=null) Lzcea+*uw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9g.5:
Utility.log(header+" : "+con.getHeaderField(header)); H!l9a
else wLvM<p7OX
break; IABF_GwF
} CT'#~~QB
} XPnHi@x
!!cN4X
[h8macx
public void splitterStop() vY,D02EMw
{ \]dvwN3x
bStop = true; Z.s0ddMs
} (CJx Y(1K
A5_r(Z-5
.kgt?r
} K}'?#a(aX=
+Y$EZL.A
IA`Lp3Z
/* SDs#w
**FileAccess.java nUisC5HW
*//文件访问(定位，写) azO7C*_
package NetFox; *55unc
import java.io.*; n8`WU3&
D#^euNiWd
iqN?'8
public class FileAccessI implements Serializable{ N:Ir63X*#
P.mlk>r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 k^zU;
RandomAccessFile oSavedFile; ^uPg71r:
long nPos; WF2t{<]^e
Dt iM}=:
0]^gT'
public FileAccessI() throws IOException o%0To{MAF-
{ iO2jT+i
this("",0); wrsr U
} JC;&]S.
K6|R ;r5e{
8NTE`l=>/
public FileAccessI(String sName,long nPos) throws IOException Qd>\{$N
{ /!`xqG#
oSavedFile = new RandomAccessFile(sName,"rw"); uf"(b"N0
this.nPos = nPos; 432]yhQ
oSavedFile.seek(nPos); yD@eT:lyi
} 5du xW>D
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eo.B0NZsF
public synchronized int write(byte[] b,int nStart,int nLen) ,zxv>8Nt
{ \Pe+]4R-Xo
int n = -1; P4+PY 8
try{ oArJ%Y>
oSavedFile.write(b,nStart,nLen); w6pXF5ur>
n = nLen; ff~1>=^
} ~qK/w0=j
catch(IOException e) K_!:oe7%
{ 9}H]4"f7
e.printStackTrace (); $+$l?2
} p+dOw#
0Q)YZ2
k|U2Mp
return n; H6U5-
} \xQu*M:!
7:<A_OLi
+oL@pp0
} \1QY=}
*kEzGgTzoS
8DM! ]L
/* ?nq%'<^^
**SiteInfoBean.java @[Q`k=h$
*/ ydAiH*>
package NetFox; syI|gANT/r
'g3T'2"`5
+(^HL3
public class SiteInfoBean { 9[sOh<W
u(\O@5a
-Zp BYX5e_
private String sSiteURL; //Site's URL gYe6(l7m
private String sFilePath; //Saved File's Path O~Bh(_R&
private String sFileName; //Saved File's Name W!Fc60>p@f
private int nSplitter; //Count of Splited Downloading File 6Rmdf>a
[AA}P/iW
(t@:dW
public SiteInfoBean() n 8 K6m(
{//nSplitter的缺省值为5 cLw|[!5:
//default value of nSplitter is 5 =%c\<<]aV
this("","","",5); K9y~ e
} )4m`Ya,E3
V Ew| N)
%%zlqd"0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k+vfZ9bD(J
{ m/ID3_
sSiteURL= sURL; A7|L|+ ?
sFilePath = sPath; "F6gV;{Bt
sFileName = sName; /bPs0>5
this.nSplitter = nSpiltter; KSHq0A6/q%
S4'<kF0z
e`OQ6|.k8
} tw&v@HUP
5$+ssR_?k
iRbe$v&N
public String getSSiteURL() *>1^q9M
{ 0/9]TIc
return sSiteURL; ivyaGAF}+o
} _x|.\j
3!vzkBr
?~!9\dek,
public void setSSiteURL(String value) &;=/^~EG
{ _A])q
sSiteURL = value; ic"8'Rwb
} tC5-^5[y
UGj |)/
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public String getSFilePath() ]5Dh<QY&.
{ ~QDM .5
return sFilePath; C+[)^2M{
} aB?usVoS
aT(_c/t.
Rn]xxa'
public void setSFilePath(String value) +jyGRSo
{ X6 N&:<
sFilePath = value; 7nFOVZ
} a^pbBDi W
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A.dbb'^
public String getSFileName() 'W yWO^Bdk
{ akU2ToP
return sFileName; 4^M"V5tDx
} :O$bsw:3w<
OZnKJ<
^YropzHZ4E
public void setSFileName(String value) &i.sSqSI5
{ 7GWOJ^)
sFileName = value; 7CvBE;i
} TEMxjowr
~!!|#A)W
_B&Lyg!J
public int getNSplitter() /of K7/
{ 2J8:_Ql3I
return nSplitter; u+KZ. n/
} J9p4\=9
H;l_;c`
-Ou.C7ol
public void setNSplitter(int nCount) tiHR&v
{ q$mc{F($D
nSplitter = nCount; ]z/R?SM
} "\KBF
} IA({RE
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kFV, Fg
/* . R/y`:1:W
**Utility.java j)6p>6
*/ yxo=eSOM
package NetFox; m<#12#D
/:'>-253
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public class Utility { >([,yMIY
3m`>D e
~IS8DW$;
public Utility() fyA-*)oHv
{ kMMgY?
$i5J}
W>)0=8#\
} mpMAhm:
R]iV;j|
//线程睡眠 ,1$F#Eh
public static void sleep(int nSecond) uMS+,dXy
{ u0 tlf
try{ gJ'pwSA
Thread.sleep(nSecond); eY5mwJ0K
} Xa?O)Bq.
catch(Exception e) 4n@lrcq(
{ J5I@*f)l
e.printStackTrace (); cN8Fn4gq
} HdJ g
} |uqI}6h.
pUb1#=
//日志 ^hmV?a:Y
public static void log(String sMsg) U`mX f#D
{ bIAE?D
System.err.println(sMsg); P<<+;']
} ,0.kg
]A'{DKR
D3X4@sM
public static void log(int sMsg) L ,dh$F
{ d*0RBgn
System.err.println(sMsg); VNHceH
} :~vodh
} At4\D+J{Vs
1x:W 3.
\}s/<Q
/* !i^"3!.l,]
**TestMethod.java 2Lf,~EV
*/ D=TS IJ@
package NetFox; 5mD8$%\8
7"!b5(4=
'bi;Y1:
public class TestMethod { dm4Q'u
` 3qf}=Z`
<m]0!ii
public TestMethod() d-D,Gx]>$
{ ///xx/weblogic60b2_win.exe yx :^*/
try{ fY[Fwjj3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m9DFnk<D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }kqh[`:
SiteFileFetch fileFetch = new SiteFileFetch(bean); .ybmJU*Hg
fileFetch.start(); w`)5(~b
} W2 -%/
catch(Exception e){e.printStackTrace ();} nn_O"fZi
]?tRO
=9GALoGL
} Q&eyqk
o utJ/~9;
?,>3uD#
public static void main(String[] args) lFjz*g2'
{ dFy$w=
new TestMethod(); s5nw<V9$]
} -3{Q`@F
} )!2@v@SQ
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