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)); LL.x11o3
} wG8 nw;
for(int i=0;i<nEndPos.length-1;i++) f0DK>L
{ 0elxA8Z~e
nEndPos = nStartPos[i+1]; wx*1*KZ
} BZ+;n |<r
nEndPos[nEndPos.length-1] = nFileLength; 6WeM rWx
} ~>g+2]Bn>$
} -9d%+O~v6~
f}iU& 3S
dw9Tf^V
//启动子线程 hO3{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wo!;K|~P
for(int i=0;i<nStartPos.length;i++) R&*@@F-dx
{ {n&Uf{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k3>YBf`fC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), H O*YBL
nStartPos,nEndPos,i); [9AM\n>g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A?A9`w
fileSplitterFetch.start(); DZk1ZLz
} f@d9Hqr+l;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yQ%"U^.m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D"^'.DL@wG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e)b%`ntF
nEndPos = " + nFileLength); gi$XB}L+X
// fileSplitterFetch[nPos.length-1].start(); Ac`;st%l.
{$33B'wk
KmmQ,e%
//等待子线程结束 2khh4?|\
//int count = 0; ~KPv7WfG
//是否结束while循环 4-^[%&>}
boolean breakWhile = false; 0[Eb .2I
)+EN$*H
|>+uw|LtZ
while(!bStop) Oaa"T8t
{ (%'9CfPx
write_nPos(); sJU`u'w
Utility.sleep(500); qybxXK:
breakWhile = true; ]iVLHVqz
/iG7MC\`
WbcS: !0
for(int i=0;i<nStartPos.length;i++) 4TZ cc|B5
{ 8:dQ._#v
if(!fileSplitterFetch.bDownOver) 5FOqv=6S
{ p$XKlg&
breakWhile = false; a <wL#Id
break; i\Wdo/c-H
} %\6Q .V#s
} s`;f2B/|
if(breakWhile) :kG)sw7
break; x-;`-Uo%
3i=Iu0
|8U;m:AS
//count++; !Z|($21W
//if(count>4) qINTCm j
// siteStop(); 6Hf,6>
} ,b|-rU\
zk}{ dG^M:
L;/n!k.A
System.err.println("文件下载结束！"); G%:GeW
} &%,DZA`
catch(Exception e){e.printStackTrace ();} =w%Oa<
} ej^3YNh&
Md&WJ };L
U(,.D}PG
//获得文件长度 :_HF j.JW
public long getFileSize() 7lA:)a_!]
{ "#4dW7E
int nFileLength = -1; sn{tra
try{ Mu&x_&|
URL url = new URL(siteInfoBean.getSSiteURL()); y{=>$C[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZA820A>2!
httpConnection.setRequestProperty("User-Agent","NetFox"); MKg,!TELe
t'(1I|7
@dEiVF`4:
int responseCode=httpConnection.getResponseCode(); /+[63=fl
if(responseCode>=400) 1@qgF
{ +B"0{>n}F
processErrorCode(responseCode); ;rR/5d1!
return -2; //-2 represent access is error $NG++N
} Mvcfk$pA
Z :nbZHByh
$k%Z$NSN=
String sHeader; s([dGD$i
{y-^~Q"z
rRb+_]Lg
for(int i=1;;i++) (.23rVvnT@
{ DL8x":;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @S3f:s0~D
//Utility.log(in.readLine()); 7o]HQ[xO
sHeader=httpConnection.getHeaderFieldKey(i); )jDJMi_[
if(sHeader!=null) 'jfRt-_-
{ >: Wau
if(sHeader.equals("Content-Length")) ^%<pJMgdF
{ 2`bdrRD0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (K<9hL+X
break; l"pN90B4
} 8dO?K*J,H'
} E6A/SVp
else ;['a
break; B\CN<<N>dD
} o\=n4;S
} HdX2YPYn;
catch(IOException e){e.printStackTrace ();} bGmx7qt#
catch(Exception e){e.printStackTrace ();} zm#nV Y`
*hY2.t; X
L%\b'fs
Utility.log(nFileLength); wkb$^mU
J/x2qQ$9
N4!<Xj
return nFileLength; @cD uhK"U}
} v"O5u%P
e2)autBe
I4c!m_sr
//保存下载信息（文件指针位置） `V!>J1x
private void write_nPos() s8mr''
{ ajH"Jy3A
try{ N#z~
output = new DataOutputStream(new FileOutputStream(tmpFile)); } cNW^4F
output.writeInt(nStartPos.length); ~Y!kB:D5;~
for(int i=0;i<nStartPos.length;i++) +OHGn;C
{ U1R4x!ym4
// output.writeLong(nPos); LIpEQ7;
output.writeLong(fileSplitterFetch.nStartPos); TnH\O$
output.writeLong(fileSplitterFetch.nEndPos); Ip *g'
} wdas1
output.close(); 3HC
} }}{Yw
catch(IOException e){e.printStackTrace ();} kxB.,'
catch(Exception e){e.printStackTrace ();} gP}+wbk
} IDFFc&
pPro }@@
5/0j}_pP
//读取保存的下载信息（文件指针位置） (p)!Mq "^
private void read_nPos() sM2MLh'D
{ `BXS)xj
try{ c-4STPNQi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dp5cDF}l
int nCount = input.readInt(); ku&k'V
nStartPos = new long[nCount]; HIvZQQW|
nEndPos = new long[nCount]; j}JZ
for(int i=0;i<nStartPos.length;i++) F7}-!
{ YwDt.6(+,
nStartPos = input.readLong(); ^QXbJJ
nEndPos = input.readLong(); Bi%x`4Lf
} 1NLg _UBOK
input.close(); {S.>BXX
} V"KS[>>f
catch(IOException e){e.printStackTrace ();} L,_.$1d
catch(Exception e){e.printStackTrace ();} a[!%Ld
} N"7]R[*
t0E51Ic@
B4H!5b
private void processErrorCode(int nErrorCode) g_.^O$}
{ t+Bf#:
System.err.println("Error Code : " + nErrorCode); :!TIK1
} FY3IUG
qSU|=
2umv|]n+l|
//停止文件下载 #1nJ(-D+
public void siteStop() TLa]O1=Bf.
{ o*S"KX$
bStop = true; Tl("IhkC
for(int i=0;i<nStartPos.length;i++) >bo'Y9C
fileSplitterFetch.splitterStop(); _GYMPq\%L#
wIvo"|%
Vm1-C<V9
} A<MtKb
} `)$_YZq|SR
//负责部分文件的抓取 0#p/A^\#7M
**FileSplitterFetch.java e]8,:Gd(
*/ Am4lEvb
package NetFox; $&I'o
5g5'@vMN
fz_nsVD
import java.io.*; ZI>km?w
import java.net.*; v $({C
KA s1(oG
afG{lWE)
public class FileSplitterFetch extends Thread { ~.g3ukt
fPa9ofU/kr
?}QH=&=^
String sURL; //File URL RVw9Y*]b
long nStartPos; //File Snippet Start Position clO,}Ph>
long nEndPos; //File Snippet End Position uKr1Z2
int nThreadID; //Thread's ID SI:ifR&T
boolean bDownOver = false; //Downing is over 2][DZl
boolean bStop = false; //Stop identical 4Ft1@
FileAccessI fileAccessI = null; //File Access interface Ukz;0q
u'~;Y.@i'
5`+5{p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j7QX,_Q
{ ?uLeFD
this.sURL = sURL; uzr\oj+>
this.nStartPos = nStart; B2=\2<
this.nEndPos = nEnd; o2H1N~e#c
nThreadID = id; WN]<q`.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'I}:!Z
} Rqipkx
tfO#vw,@
<[ Xw)/#
public void run() S56]?M|[
{ I3b"|%
while(nStartPos < nEndPos && !bStop) [I*! lbt
{ mB'3N;~
jdA ]2]
v-j3bB
try{ \K2*Q&>
URL url = new URL(sURL); o89( h!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6aft$A}XnD
httpConnection.setRequestProperty("User-Agent","NetFox"); nSx8E7 |V
String sProperty = "bytes="+nStartPos+"-"; -T@`hk`
httpConnection.setRequestProperty("RANGE",sProperty); ~EiH-z4U
Utility.log(sProperty); PyC0Q\$%
(?)7)5H
X@N$Z{
InputStream input = httpConnection.getInputStream(); U\@A_ B
//logResponseHead(httpConnection); w*7|dZk{
Wzq>JNny
-Yi,_#3{
byte[] b = new byte[1024]; )Q;978:
int nRead; KxGX\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {2d_"lHBt
{ $RX'(/
nStartPos += fileAccessI.write(b,0,nRead); Sb2v_o
//if(nThreadID == 1) +xv!$gJEj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @exey
} oih5B<&f#
{^)70Vz>PE
Pn.bVV:
Utility.log("Thread " + nThreadID + " is over!"); K+\nC)oG
bDownOver = true; AEirj /
//nPos = fileAccessI.write (b,0,nRead); "d/s5sP|S
} '_s}o<
catch(Exception e){e.printStackTrace ();} {Bvj"mL]j
} F?+3%>/A@
} {BBw$m,o
RrrK*Fk8=
W[bmzvJ_X
//打印回应的头信息 ;E;To\NCYF
public void logResponseHead(HttpURLConnection con) E`\8TqO
{ +]xFoH
for(int i=1;;i++) %hS|68pN6
{ e'*HS7g
String header=con.getHeaderFieldKey(i); Y qdWctUY
if(header!=null) jjs&`Fy,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~!iQ6N?PY
Utility.log(header+" : "+con.getHeaderField(header)); B/f0P(7
else }alj[)
break; B1 0+*p(
} #^#Kcg
} I`RBj`IF
klOp ^w
rnFM/GAy
public void splitterStop() kfb/n)b'
{ ]DG?R68DQ
bStop = true; }ucIH@U{
} 9-1#( Y6S
VaZn{z
*O$CaAr\s
} f|EUqu%E
7v}x?I
;^u*hZN[Up
/* q z&+=d@
**FileAccess.java t G.(flW,
*//文件访问(定位，写) m4w')r~
package NetFox; )emOKS
import java.io.*; F!!N9VIC
o5o^TW{
l3o#@sz:
public class FileAccessI implements Serializable{ u0)7i.!M
[dX`K`k
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z2c5m
RandomAccessFile oSavedFile; M(q'%XL^
long nPos; 4EP<tV
DC+wD Bp;
SS|z*h Z
public FileAccessI() throws IOException ;oOv/3
{ v`[Eb27W.
this("",0); N^0uit
} i8X`HbmN
;Q0bT`/X
=1;=
public FileAccessI(String sName,long nPos) throws IOException @ez Tbc3
{ K ?$#ntp
oSavedFile = new RandomAccessFile(sName,"rw"); !<@J6??a}s
this.nPos = nPos; ^nK7i[yF.k
oSavedFile.seek(nPos); gYop--\14]
} uwIc963
.ae O}^
Q/>L_S
public synchronized int write(byte[] b,int nStart,int nLen) 2GmpCy`L"
{ S]3Ev#>
int n = -1; R\Z:n*
try{ NF$\^WvYSP
oSavedFile.write(b,nStart,nLen); N[|Nxm0z/C
n = nLen; X~.f7Ao[
} &xZyM@
catch(IOException e) ~`#-d ^s:
{ OK|qv[
e.printStackTrace (); " K*
} xFv;1Q
JOnyrks
4JIYbb-a'
return n; lG<hlYckv
} I,6/21kO
p4u5mM
"I- w
} ,38Eq`5&W
Tsb{25`+
'fwU]Hm
/* &sVvWNO#2
**SiteInfoBean.java {Z;t ^:s#
*/ @gGRm
package NetFox; 6~meM@
DrW#v-d
?wpB`
public class SiteInfoBean { VxO%rq3
M.}7pJ7f
#b0{#^S:
private String sSiteURL; //Site's URL _1Z=q.sC
private String sFilePath; //Saved File's Path lt'I,Xt
private String sFileName; //Saved File's Name Eu<1Bse;
private int nSplitter; //Count of Splited Downloading File Mq%,lJA\
7YWNd^FI V
HHk)ZfWRo
public SiteInfoBean() ni&*E~a
{//nSplitter的缺省值为5 6X g]/FD
//default value of nSplitter is 5 }*U[>Z-eO
this("","","",5); 2Nc>6
} @{ ;XZb^
:B*}^g
uUR~&8ERX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) M<?Q4a'Q
{ %%%fL;-y
sSiteURL= sURL; uv{P,]lK
sFilePath = sPath; Jc4L5*Xn/
sFileName = sName; cX!Pz.C
this.nSplitter = nSpiltter; XV>JD/K2
YOyX[&oi
rPzQ8<
} sPAg)6&M
0Rxe~n1o
+m\|e{G
public String getSSiteURL() }peBR80tQ
{ [BbutGvj
return sSiteURL; 1MkI0OZE
} J<j&;:IRd
dpZ;l 9
9$K;Raz%
public void setSSiteURL(String value) ?0*8RK
{ 9|'B9C
sSiteURL = value; }71LLzG`/
} /Poet%XvRx
ZsP2>%"
I XA>`D
public String getSFilePath() (n( fI f
{ ~!6K]hB4
return sFilePath; JeH;v0
} t/i5,le
C2e.2)y
%n0;[sD0A
public void setSFilePath(String value) UnWW/]E
{ a.F Al@Br
sFilePath = value; )8gGv
} sE(HZR1
8Ad606
%6j)=IOts
public String getSFileName() Q<tu)Qo
{ 4NEq$t$Jn
return sFileName; zQy"m-Q
} 3ucP(Ex@tg
CCijf]+
6w3R'\9
public void setSFileName(String value) nHFrG =o,
{ "LhUxnll
sFileName = value; .o{0+fC#
} 1tzV8(7
pI`?(5iK6|
}H:F< z*
public int getNSplitter() z|R,&~:
{ w [>;a.$
return nSplitter; &YP#M|
} #eP LOR&q
2B~wHv
lkIn%=Z
public void setNSplitter(int nCount) z5\;OLJS,
{ -php6$|
nSplitter = nCount; Ths_CKwgWY
} /RZR}
} %9C@ Xl
B=L&bx
j'%4{n
/* iItcN;;7
**Utility.java 4\t1mocCSN
*/ W~T}@T:EN
package NetFox; #PvB/3
!{,F~i9
EC&@I+'8Q
public class Utility { PrQ?PvA<L
vEM(bT=H
Zx }&c |Q
public Utility() Z]w#vLR
{ /h2b;"
bte~c
{'+QH)w(
} z"4]5&3A
XK(`mEi
//线程睡眠 +KGZHO!
public static void sleep(int nSecond) =]R3& ]#n
{ 0X2@CPIFf
try{ MWk:sBCqr
Thread.sleep(nSecond); ;#GoGb4AM
} jd`},X/
catch(Exception e) S&C1TC
{ X8eJ4%
e.printStackTrace (); A?Qa 4i
} GnXNCeE`
} ivgpS5 M`Y
vh!v MB}}
//日志 wu<])&F
public static void log(String sMsg) Bc-yxjsw
{ SZ![%)83
System.err.println(sMsg); S/vf'gj
} v<\A%
" }gVAAvc7
q}uHFp/J
public static void log(int sMsg) W_O)~u8
{ +Z2MIC|Ud
System.err.println(sMsg); 3 vP(SIF
} 5M]z5}n/
} {MAQ/5
;32#t[ib
Ax3W2s
/* )Ag/Qep
**TestMethod.java (<t_Pru
*/ 9ILIEm:
package NetFox; tHD
`;,Pb&W~
p_*M:P1Ma4
public class TestMethod { YO{GU7
m^%|ZTrwN7
?i\B^uB
public TestMethod() M/PFPJ >`
{ ///xx/weblogic60b2_win.exe 9n]|PEoAB
try{ p5=|Y^g !
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?8dVH2W.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y<R=
SiteFileFetch fileFetch = new SiteFileFetch(bean); PeX1wK%f
fileFetch.start(); !2CL1j0(
} $m1<i?'m
catch(Exception e){e.printStackTrace ();} YIt9M,5/Q
M x5`yT7
%HQ.|
} FFhtj(hVgc
1 "TVRb
=6FUNvP#8
public static void main(String[] args) gV1[3dW
{ ?71+f{s
new TestMethod(); (%CZ*L[9Z
} Ph&urxH@
} P27%xV-n>
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