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)); |$Xl/)Oq
} y.WEj?EL
for(int i=0;i<nEndPos.length-1;i++) nQ q=7Gu
{ @2Z#x
nEndPos = nStartPos[i+1]; t?}zdI(4
} S`#w+C#EW
nEndPos[nEndPos.length-1] = nFileLength; .q9 $\wM/
} pPcTrN'
} <_3b1VhZ
o$w_Es]Ma
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//启动子线程 {B[=?6tQ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B[V+ND'(
for(int i=0;i<nStartPos.length;i++) KVD8YfF
{ Z?%zgqTXb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A9wh(P0\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cm?\ -[cV
nStartPos,nEndPos,i); W}5xmz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N'g>MBdI
fileSplitterFetch.start(); bsB*533
} _tBTE%sO
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {5F-5YL+>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @^T1XX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~nrK>%
nEndPos = " + nFileLength); So0f)`A
// fileSplitterFetch[nPos.length-1].start(); 4WJ.^(
,QcF|~n
jg.QRny^
//等待子线程结束 *.!Np9l,V
//int count = 0; KTP8?Q"n0
//是否结束while循环 #`o2Z
boolean breakWhile = false; %d?cP}V
D|Q#gcWpo
j!]YNH@
while(!bStop) O+]Ifm[
{ CCL
write_nPos(); G&4&-<
Utility.sleep(500); a>GyO&+Dkg
breakWhile = true; `[W[H(AjQ
LN@F+CyDc
i'#E)
for(int i=0;i<nStartPos.length;i++) mGJasn
{ ie2WL\tR4
if(!fileSplitterFetch.bDownOver) n p\TlUc
{ /+@p7FqlE
breakWhile = false; `QyO`y=?[Y
break; hRK/T7v
} A1.7O
} "x3lQ
if(breakWhile) ~])t 6i
break; YgUvOyaQXf
R,pX:H&#+
px}|Mu7z~
//count++; ?XA2&
//if(count>4) oxz OA
// siteStop(); @wE5S6! B\
} d` jjGEj
vTlwRG=5
m^GJuPLW
System.err.println("文件下载结束！"); :}@g6
} a2 Y;xe
catch(Exception e){e.printStackTrace ();} bO'Sgc[]
} Q\ U:~g3
o1FF"tLkN
*Df,Ijh$
//获得文件长度 j(RWO
public long getFileSize() dIRm q+d^
{ p;tVn{u
int nFileLength = -1; ~%SH3$
try{ c6X}2a'
URL url = new URL(siteInfoBean.getSSiteURL()); 763v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ni<A3OB
httpConnection.setRequestProperty("User-Agent","NetFox"); BV>\ McI+
V>A.iim
,!7 H]4Qx
int responseCode=httpConnection.getResponseCode(); ReM=eS
if(responseCode>=400) ML( Eo
{ nij!1z|M
processErrorCode(responseCode); ;S57w1PbVA
return -2; //-2 represent access is error k;w- E
} Cb9;QzBVA#
-lhLA`6_R
* v75O7l
String sHeader; B:!W$<
\ aHVs
V??dYB(
for(int i=1;;i++) Lz:(6`S
{ }lfnnK#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L7VG`h;
//Utility.log(in.readLine()); "QWq_R
sHeader=httpConnection.getHeaderFieldKey(i); ^V#@QPK9
if(sHeader!=null) yp66{o
{ 1$%V{4bJ
if(sHeader.equals("Content-Length")) xYhrO
{ Er+nk`UR_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); m"o ;L3
break; Zxbo^W[[
} <K8\n^i~c
} ^Nmg07_R
else {6~l$
break; \'CDRr"uw
} qUOKB6
} AKRTBjG"
catch(IOException e){e.printStackTrace ();} JXu$ew>q
catch(Exception e){e.printStackTrace ();} ^9ePfF)5
~R&;v3
l"2OP6d
Utility.log(nFileLength); !ykx^z
Vgyew9>E
sH?/E6
return nFileLength; YJl("MZ
} S}ECW,K
>$,y5 AJ&
^4`Px/&
//保存下载信息（文件指针位置） Tp9-niW
private void write_nPos() =n' 4?W@
{ ea00\
try{ y:h}z).
output = new DataOutputStream(new FileOutputStream(tmpFile)); dGFGr}&s
output.writeInt(nStartPos.length); ^+m+zd_
for(int i=0;i<nStartPos.length;i++) O=dJi9;`#_
{ E)9yH\$6
// output.writeLong(nPos); kr9gK~
output.writeLong(fileSplitterFetch.nStartPos); HCa
output.writeLong(fileSplitterFetch.nEndPos); p!<$vE
} sqS=qC
output.close(); !grVR157P
} "/nNM{^
catch(IOException e){e.printStackTrace ();} /g$G_}
catch(Exception e){e.printStackTrace ();} x $zKzfHW
} ocyb5j
.]9c/
_C+b]r/E
//读取保存的下载信息（文件指针位置） bug Ot7
private void read_nPos() a+9*@z2
{ ;9}pOzF1q
try{ 4#'("#R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5&e<#"
int nCount = input.readInt(); R3!@?mcr
nStartPos = new long[nCount]; 03iv3/{H
nEndPos = new long[nCount]; G5,~Z&}YS
for(int i=0;i<nStartPos.length;i++) wV)}a5+
{ j}AFE
nStartPos = input.readLong(); MCP "GZK6W
nEndPos = input.readLong(); n?:=
} PDLpNTBf
input.close(); @Kgl%[NmX
} _zu?.I0^
catch(IOException e){e.printStackTrace ();} 033T>qY
catch(Exception e){e.printStackTrace ();} P/ oXDI8
} `+/H^
u?[ q=0.J7
\@;\t7~
private void processErrorCode(int nErrorCode) ~kCwJ<E
{ ?~QIALA
System.err.println("Error Code : " + nErrorCode); L}yyaM)
} )*5G">))p
c=6Q%S
'>v^6iS
//停止文件下载 R <"6ojn
public void siteStop() e62Dx#IY
{ ((rv]f{
bStop = true; 5`<eKwls
for(int i=0;i<nStartPos.length;i++) {R^'=(YFy
fileSplitterFetch.splitterStop(); c:l]=O
dtAbc7
e2C<PGUUB
} rz(0:vxwA
} C`'W#xnp1
//负责部分文件的抓取 %o}(sShS
**FileSplitterFetch.java ntP|\E
*/ 9Z6C8Jv
package NetFox; 3g~^LZ66
?R5'#|EyX
G5tday~3
import java.io.*; &)pK%SAM
import java.net.*; !eJCM`cp
D^Ys)- d
fRm}S>Nibb
public class FileSplitterFetch extends Thread { jvzBh-!
1zktU.SZ
4UAvw
String sURL; //File URL Yn9j-`
long nStartPos; //File Snippet Start Position w.N,)]h
long nEndPos; //File Snippet End Position Vdn.)ir~P
int nThreadID; //Thread's ID G*\h\@
boolean bDownOver = false; //Downing is over ~@8+hnE]
boolean bStop = false; //Stop identical K<v:-TjQZ:
FileAccessI fileAccessI = null; //File Access interface y7<&vIEC
4(vyp.f
Oe1 t\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &14W vAU
{ K%}}fw2RMN
this.sURL = sURL; P ,K\
this.nStartPos = nStart; S:Tm23pe
this.nEndPos = nEnd; T`$KeuL
nThreadID = id; -cNx1et
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (OQ?<'Qa
} !;>(ie\
PdY>#Cyh
#1$}S=8*f
public void run() ;^l_i4A
{ X9~m8c){z
while(nStartPos < nEndPos && !bStop) -O&"|
{ DM3B]Yl
JZ`L%
T{*^_
try{ L)-*,$#<oW
URL url = new URL(sURL); Fc0jQ@4=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0^]t"z5f0
httpConnection.setRequestProperty("User-Agent","NetFox"); lVeH+"M?
String sProperty = "bytes="+nStartPos+"-"; 'o\;x"YJ
httpConnection.setRequestProperty("RANGE",sProperty); 2/tb6' =
Utility.log(sProperty); %OI4a5V*l
A|<;
7o{*Z
InputStream input = httpConnection.getInputStream(); &]nd!N
//logResponseHead(httpConnection); sT<{SmBF
,0T)Oc|HL/
?^3B3qqh9
byte[] b = new byte[1024]; MM_py!=>7
int nRead; b*9e1/]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >rwYDT#m]
{ MOV =n75
nStartPos += fileAccessI.write(b,0,nRead); *5wv%-
//if(nThreadID == 1) Pi%tsKk%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v+tO$QZ`
} 'P/taEi=R
II#
N&B>#:
Utility.log("Thread " + nThreadID + " is over!"); /v&`!nKu
bDownOver = true; q<}PM
//nPos = fileAccessI.write (b,0,nRead); 5c~'!:7
} DN|vz}s
catch(Exception e){e.printStackTrace ();} R+^zy"~
} 70<K.T<b
} L;C|ow^c
&5/JfNe3
P7 8uq
//打印回应的头信息 3ExVZu$
public void logResponseHead(HttpURLConnection con) f)tc4iV
{ ?W<cB`J
for(int i=1;;i++) K|~AA"I;
{ +GPd
String header=con.getHeaderFieldKey(i); 0(vdkC4\A
if(header!=null) 9<qx!-s2rr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); iJ*%dio
Utility.log(header+" : "+con.getHeaderField(header)); [5LMt*Y
else #,Bj!'Q'-
break; g!5#,kJM
} 3It8&x:
} 7n>|D^
-~0'a
L3>4t: 8
public void splitterStop() )Jz!Ut
{ 4i96UvkZ
bStop = true; %rFllb7
} |Qq+8IeYG
5YLho2h38!
^B6`e^<
} tQ6|PV
!z.^(Tj
(aBP|rxg
/* 8\u;Wf
**FileAccess.java 1[# =,
*//文件访问(定位，写) ?xf~!D
package NetFox; ILIRI[7(
import java.io.*; p?KCVvx$
J b|mXNcL
~JT lPU'
public class FileAccessI implements Serializable{ _qk9o
>0ssza
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5M]6'X6I
RandomAccessFile oSavedFile; _4g}kL02.
long nPos; Z^C!RSQ
W|FNDP0
lTd+{TF.
public FileAccessI() throws IOException FJ nG<5Rh
{ o^N%;d1%E
this("",0); rjt O`Mt`
} c '/2F0y
F'fM?!(
'$lw[1
public FileAccessI(String sName,long nPos) throws IOException "F04c|oR<X
{ C3^X1F0
oSavedFile = new RandomAccessFile(sName,"rw"); chMt5L+5
this.nPos = nPos; s 0 =@ &/
oSavedFile.seek(nPos); !Q\X)C
} d8 3+6d
cM|af#o
CA'hvXb.
public synchronized int write(byte[] b,int nStart,int nLen) r(748Qc4f?
{ V:$[~)k8
int n = -1; (%=lq#,
try{ ^2(";.m
oSavedFile.write(b,nStart,nLen); u~j'NOv
n = nLen; |J@|
} ^2P;CAjj-
catch(IOException e) bi,rMgW
{ }d$vcEI$3
e.printStackTrace (); ">v_uq a
} jCdZ}M($
-uS7~Ww.a
B]CS2LEqh
return n; 7~QwlU3n<F
} &ij^FAM
V_ avaE
C:TuC5Sr
} 5[0l08'D
kY0g}o'<
D z]}@Z*jK
/* 4 g/<).1<b
**SiteInfoBean.java $/-wgyP3m+
*/ %u<&^8EL+#
package NetFox; :$u{
=[O<.'aG-
vs)HbQ
public class SiteInfoBean { Yn?2,^?N
~gcst;
C=pPI
private String sSiteURL; //Site's URL $rV:&A
private String sFilePath; //Saved File's Path QvT-&|
private String sFileName; //Saved File's Name Ve')LY<
private int nSplitter; //Count of Splited Downloading File 7m@^=w
Uzm[e%/`
#RZJ1uL
public SiteInfoBean() cnjj) c
{//nSplitter的缺省值为5 Q?I"J$]&L
//default value of nSplitter is 5 Xk7$?8r4&
this("","","",5); { ?1mY"
} kcZ;SYosj
y("0Xve
IQIb\OUo!v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bx%hizb
{ .w*{=x0k
sSiteURL= sURL; *<h
sFilePath = sPath; j#.-MfB
sFileName = sName; FZ'>LZ
this.nSplitter = nSpiltter; C.TCDl
bQnwi?2
sou$qKoG01
} e&]`X HC9
t&?v9n"X
PtVNG
public String getSSiteURL() |jCE9Ve#
{ )v$Cv|"
return sSiteURL; ,uD*FSp>
} L)//- k9
H)}1xQ{3F
a\2Myj
public void setSSiteURL(String value) J\8l%4q3
{ u=UM^C!
sSiteURL = value; Wx\"wlJ7.3
} PXQ9P<m
p?gLW/n
t>=y7n&q
public String getSFilePath() A#07Ly8kXn
{ V{^fH6;[
return sFilePath; f"=4,
} b42pLbpe'E
?lw[
oG_'<5Bv>
public void setSFilePath(String value) {&j{V-}f
{ UDi3dH=
sFilePath = value; %'~<:>:"E
} Q Fqv,B\<
:phD?\!w8t
";Xbr;N
public String getSFileName() OL9C#er
{ RxeRO2
return sFileName; 7JwWM2N?V
} z=h5
Da[X HUk
jW0z|jr
public void setSFileName(String value) !'t2
{ KI QBY!N+
sFileName = value; :/[ZgreN6
} JfINAaboi
Tb6x@MorP
9: |K]y
public int getNSplitter() [(UqPd$
{ l@F e(^5E
return nSplitter; : MmXH&yR
} 9i[2z:4HJ
bQQ/7KM
B148wh#r
public void setNSplitter(int nCount) 9wJmX<Rm
{ snNg:rTL
nSplitter = nCount; j/IZm)\
} j1CD;9i)%
} pXlBKJmW
$^aXVy5p
)H,<i{80c
/* fw};.M
**Utility.java KgAX0dM
*/ >-+X;0&
package NetFox; DL!s)5!M
3VBV_/i;
%4^/.) Q
public class Utility { |OT%,QT|
SLB iQd.
<aD+Ki6
public Utility() HUI!IOh
{ Y }d>%i+
LKY Q?
Mxp4YQl
} oh~Dbu=%
bxHk0w
//线程睡眠 yiA\$mtO
public static void sleep(int nSecond) 8rNxd=!
{ NVPYv#uK
try{ "t`e68{Ls
Thread.sleep(nSecond); 4rdrl
} R:<AR.)K
catch(Exception e) >R-$JrU.=
{ 9K(b Z{
e.printStackTrace (); 'z5 ;o:T
} $MGd>3%y
} P=z':4,M}
Ob+c*@KiW
//日志 v1rGq
public static void log(String sMsg) jGPs!64f)
{ M#|xj <p
System.err.println(sMsg); ^jA^~h3(W
} ~vS.Dr
%hQ`b$07t
BpE[9N
public static void log(int sMsg) @)wXP@7
{ ?-i&6i6Y
System.err.println(sMsg); Y?x3JU0_
} $]86w8?-N
} hNfL /^w
``D-pnKK
2x CGr>X
/* [c~zO+x
**TestMethod.java wDzS<mm
*/ vzPrG%Uu7g
package NetFox; :-n4!z"k
l-rI|0D#
BZsxf'eN'
public class TestMethod { #4?3OU#
+q!6zGs.
{fs(+ 0ei
public TestMethod() :a2?K5
{ ///xx/weblogic60b2_win.exe i=rW{0c%
try{ bcg)K`'N
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :mL.Y em*'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f.WtD`Oas
SiteFileFetch fileFetch = new SiteFileFetch(bean); +`xp+Q
fileFetch.start(); bK7DGw`1
} 4l:+>U@KU
catch(Exception e){e.printStackTrace ();} A2 rRYzN;
ZO}*^
TDFv\y}yc
} 9i@*\Ada
oUH\SW8?
b $!l*r
public static void main(String[] args) 08Gr
{ ]|oqJ2P
new TestMethod(); W\/0&H\i
} b`' ;`*AN+
} OpfFF;"A'
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