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$$h6P#
} Z 4i5,f
for(int i=0;i<nEndPos.length-1;i++) FG+pR8aA$
{ %&VI-7+K
nEndPos = nStartPos[i+1]; m@+QC$6S
} FN<>L0
nEndPos[nEndPos.length-1] = nFileLength; XP0;Q;WF}
} =nc;~u|]
} uDkX{<_Xe
Ba5*]VGG
/kK!xe
//启动子线程 )=X g
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LyNmn.nN
for(int i=0;i<nStartPos.length;i++) cYe2a"
{ OFmHj]I7=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vnVT0)Lel
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &+A78I
nStartPos,nEndPos,i); a#i|)[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `q*p-Ju'
fileSplitterFetch.start(); [7HBn
} >i >|]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hcRe,}wJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }uC]o@/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,Eh]Zv1AE
nEndPos = " + nFileLength); e1E_$oJP
// fileSplitterFetch[nPos.length-1].start(); ot2zY dWAz
>`a^E1)
k'N``.
//等待子线程结束 J?X{NARt
//int count = 0; CueC![pj
//是否结束while循环 !G[%; d
boolean breakWhile = false; <-b9 )>
wd<{%qK`{
&Wb"/Hn2
while(!bStop) 4%8den,|
{ }N(gP_?n
write_nPos(); f(blqO.@l
Utility.sleep(500); 4r~K`)/S'
breakWhile = true; z_lKq}^~6
@R%qP>_
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for(int i=0;i<nStartPos.length;i++) ~8mz.ZdY
{ Ee7+ob
if(!fileSplitterFetch.bDownOver) %`T}%B
{ 3h=kn@I
breakWhile = false; 9_jiUZFje
break; .;Gx.}ITG6
} }0]uA|lH*
} K$qY^oyQFw
if(breakWhile) y9/nkF1p
break; .N.RpRz{f
]dJ"_
(7b9irL&cn
//count++; +_pfBJ_$%
//if(count>4) |?{V-L
// siteStop(); Ly^bP>2i
} /ILd|j(e
{5X,xdzR
Q8h0.(#-
System.err.println("文件下载结束！"); )$i,e`T
} $.d,>F6
catch(Exception e){e.printStackTrace ();} S ;rd0+J
} 3T0-RP*
n-jPb064
0k16f3uI
//获得文件长度 (.@peHu)#
public long getFileSize() 9{Etv w
{ %]0?vw:;j
int nFileLength = -1; CR9wp]-Vd
try{ wf]?:'}
URL url = new URL(siteInfoBean.getSSiteURL()); %!nN<%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _z BfNz9D
httpConnection.setRequestProperty("User-Agent","NetFox"); Udtz zka
'fb\t,
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int responseCode=httpConnection.getResponseCode(); 2AhfQ%Y=
if(responseCode>=400) pKq[F*Lut
{ Xy K,
processErrorCode(responseCode); bsU$$;
return -2; //-2 represent access is error m^qFaf)6
} 2 G*uv+=
[Z:P{yr
u1y>7,Z6W
String sHeader; YU[#4f~
JZxA:dg l
P%l?C?L
for(int i=1;;i++) xcmg3:s
{ Wj|W B*B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :X'B K4EN
//Utility.log(in.readLine()); &a=rJvnIO&
sHeader=httpConnection.getHeaderFieldKey(i); .4"BN<9
if(sHeader!=null) v.C
{ XPMUhozV
if(sHeader.equals("Content-Length")) pA_u;*
{ #\Y`?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N_B^k8j
break; G,?a8(
} KyVzf(^
} {p/Yz#
else -['& aey}a
break; Km= Y^x0
} /LWk>[Z;
} ^8,prxaok
catch(IOException e){e.printStackTrace ();} DDGDj)=`
catch(Exception e){e.printStackTrace ();} 8VQ!&^9!U#
#>:S&R?2t
YV|_y:-
Utility.log(nFileLength); g7hI9(8+
A. tGr(r
JS m7-p|E
return nFileLength; Nk\ni>Du3
} qCrpc=
BI,]pf;GWv
&)tv4L&
//保存下载信息（文件指针位置） 9<3}zwJ
private void write_nPos() __tA(uA
{ Jv3G\9_
try{ =e#h;x2
output = new DataOutputStream(new FileOutputStream(tmpFile)); hV,T889'
output.writeInt(nStartPos.length); Q~wS2f`)
for(int i=0;i<nStartPos.length;i++) fOSk> gK
{ P~!,"rY
// output.writeLong(nPos); )ej1)RU"
output.writeLong(fileSplitterFetch.nStartPos); JK!`uG+v
output.writeLong(fileSplitterFetch.nEndPos); ](s5;ta
} .kuNn-$
output.close(); ,Il) tH
} nPI$<yW7F
catch(IOException e){e.printStackTrace ();} LD?\gK"
catch(Exception e){e.printStackTrace ();} 1QmOUw}yj
} (:E@kpK
!a\v)R
I`IW^eZM
//读取保存的下载信息（文件指针位置） yLCMu | +
private void read_nPos() d42Y`Wu
{ 2eRk_j]
try{ Ue;Z)}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1I'Q{X&B
int nCount = input.readInt(); lAo~w
nStartPos = new long[nCount]; 4*f+np
nEndPos = new long[nCount]; ^.@%n1I"5y
for(int i=0;i<nStartPos.length;i++) ^b5+A6?
{ (?(gz#-
nStartPos = input.readLong(); "S'Yn-
nEndPos = input.readLong(); !+Y+P?
} (AjgLNB
input.close(); fsEQ4xN'
} $i<+O,@-
catch(IOException e){e.printStackTrace ();} W58?t6! =
catch(Exception e){e.printStackTrace ();} T3=h7a %=
} "R)n1,0
E+<GsN]
\X(*JNQ
private void processErrorCode(int nErrorCode) zXlerQWUv
{ lq3D!+m
System.err.println("Error Code : " + nErrorCode); l\N2C4NG
} -\%5aXr
r~QE}00@^
^%Y-~yB-
//停止文件下载 WZ!zUUp}V
public void siteStop() 54WX#/<Yik
{ Au)~"N~p?
bStop = true; $Q'LDmot
for(int i=0;i<nStartPos.length;i++) "B+F6
fileSplitterFetch.splitterStop(); o>+mw|{
+CSv@ />3
gWjr|m<
} x_-V{ k
} Fo;J3<U)
//负责部分文件的抓取 Jo;&~/V
**FileSplitterFetch.java S^D@8<6GJ
*/ 1VG]|6f
package NetFox; }|8^+V&
'ks .TS&
s%vy^x29
import java.io.*; `) ],FE*:
import java.net.*; {=J:
#k &#d9}
y}={S,z%22
public class FileSplitterFetch extends Thread { @}PX:*c
()t~XQ
!L9]nO 'BL
String sURL; //File URL :?ZrD,D
long nStartPos; //File Snippet Start Position _e8v12s
long nEndPos; //File Snippet End Position "u$XEA
int nThreadID; //Thread's ID <0~1
boolean bDownOver = false; //Downing is over up8d3
boolean bStop = false; //Stop identical y.8nzlkE{
FileAccessI fileAccessI = null; //File Access interface X$Q.A^9
:p)^+AF"5
};P=|t(r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W)o*$cu
{ g$Vr9MH
this.sURL = sURL; hc0$mit
this.nStartPos = nStart; o F_rC[
this.nEndPos = nEnd; 0/!0W%f[}
nThreadID = id; jyyig%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p9\*n5{
} -jrAk
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!OPHS^L
public void run() O/(vimx.#F
{ h|Qb:zEP,
while(nStartPos < nEndPos && !bStop) z_KCG2=5
{ GA[bo)"
!5[SNr3^
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try{ #s>'IPc0
URL url = new URL(sURL); ku}`PS0UGd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }1Mf0S
httpConnection.setRequestProperty("User-Agent","NetFox"); EASmB
String sProperty = "bytes="+nStartPos+"-"; Q9f5}
httpConnection.setRequestProperty("RANGE",sProperty); *6=9 8C4I
Utility.log(sProperty); =^{MyR7
s!MD8ia
.EjR<UU
InputStream input = httpConnection.getInputStream(); [C;Neslo
//logResponseHead(httpConnection); H=Cj/jE
J 48$l(l3
/e|qyWs
byte[] b = new byte[1024]; '+g[n
int nRead; ,BGUIu6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ){eQ.yW
{ Nx*1m BC
nStartPos += fileAccessI.write(b,0,nRead); W*(- *\1[
//if(nThreadID == 1) c1y+kvv
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y2dml!QM
} vLq%k+D#
W|n$H`;R
OqF8KJnO;
Utility.log("Thread " + nThreadID + " is over!"); i-@V
bDownOver = true; <1*\ ~CX
//nPos = fileAccessI.write (b,0,nRead); &u6n5-!v
} GM)q\Hx{
catch(Exception e){e.printStackTrace ();} /P]N40_@
} :kwDa a
} gLZJQubz 6
E:A!tu$B
Z6Kp-z(l3
//打印回应的头信息 C6@*l~j
public void logResponseHead(HttpURLConnection con) L=C#E0{i
{ OZ"76|H1`
for(int i=1;;i++) tuuwoiQ*`
{ 1Qz@
String header=con.getHeaderFieldKey(i); '<1Cta`
if(header!=null) T:|p[Xbo
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]A#:Uc5
Utility.log(header+" : "+con.getHeaderField(header)); \l 8_aj
else ObS#aRq
break; V U5</si+
} J}#2Wy^{
} # kNp);
U&a(WQV9&
'}bmDb*
public void splitterStop() T*8K.yw2
{ ^~@3X[No
bStop = true; 6uUn
} zM<L_l&
5tZ0zr
ssoE,6kS
} X{6a
8.I3%u
?<8c
/* asLrXGGyT
**FileAccess.java j?k|-0
*//文件访问(定位，写) bz~aj}"`
package NetFox; EN}XIa>R
import java.io.*; [fo#){3K
a1%}Ee
3#>%_@<
public class FileAccessI implements Serializable{ Y3(I;~$!
.c__T{<)[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b0@K ~O;g
RandomAccessFile oSavedFile; Z5)v
long nPos; IA]wO%c
R osU~OK
vX}w_Jj>
public FileAccessI() throws IOException d~h;|Bl[
{ ]+B.=mO_
this("",0); M7 kWJ
} `ah|BV
Hz==,NR-W
6iF&!Fd>J
public FileAccessI(String sName,long nPos) throws IOException U|\ .)h=
{ <o*b6m%
oSavedFile = new RandomAccessFile(sName,"rw"); B I3fk
this.nPos = nPos; 6%>'n?
oSavedFile.seek(nPos); Ht\2 IP
} UX<-jY#'V
k_zn>aR$F
`YE=B{q
public synchronized int write(byte[] b,int nStart,int nLen) g;nLR<]
{ eMmNQRmH
int n = -1; [m6+I9
try{ bqp^\yu-E
oSavedFile.write(b,nStart,nLen); t,*1=S5
n = nLen; MuP>#Vk
} .QwB7+V4
catch(IOException e) Q.h.d))
{ !cM<&3/
e.printStackTrace (); )Ho"b
} uozq^sy
ZZTf/s*
llWY7u"
return n; Th*}U&
} \0_jmX]p
HpfZgkC+
]vn*eqd
} vTK8t:JQ~
/~f[>#
jX(${j<
/* U=69q]
**SiteInfoBean.java (FaYagD
*/ 4Y2I'~'
package NetFox; G e]NA]<
,Tegrz&G
r=vY-p
public class SiteInfoBean { 6-TYOUm
Jvsy 6R
D M+MBK
private String sSiteURL; //Site's URL !X~NL+
private String sFilePath; //Saved File's Path dzAumWoh
private String sFileName; //Saved File's Name 5p S$rf
private int nSplitter; //Count of Splited Downloading File =N{?ll6x7g
H@$K/
[MwL=9;!H
public SiteInfoBean() D6&P9e_5
{//nSplitter的缺省值为5 rr1'| k"
//default value of nSplitter is 5 UXdc'i g
this("","","",5); fKqr$59>
} Cb? !+U
c$2kR:
CrL9|78
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4dCXBTT
{ CLVT5pj='
sSiteURL= sURL; vN],9q
sFilePath = sPath; b|DU
sFileName = sName; p#]9^oA
this.nSplitter = nSpiltter; )xa)$u
oST)E5X;7
R8u8jG(4
} 'iZwM>l\
7qOkv1.}0
Y,Z$U| U
public String getSSiteURL() YjTr49Af0
{ [m h>N$
return sSiteURL; Ot`%5<E^
} %M'`K
uj.$GAtO)
y'odn;
public void setSSiteURL(String value) (:`4*xK
{ |^UQVNJ
sSiteURL = value; yx-"&K=`
} uKM` umE
cyB+(jLHDs
iBbaHU*V
public String getSFilePath() H7&y79mB
{ S}U_uZ$b
return sFilePath; ^" g?m
} TsoxS/MI"
.$x}~Sw
=CD6x= l6
public void setSFilePath(String value) ?zutU w/m
{ !J#P'x0
sFilePath = value; x/M$_E<G
} /ZabY
\M@IKE
rCA!b"C2
public String getSFileName() Nh^I{%.x
{ XfVdYmii
return sFileName; HP[B%
} NJr)f
y|MhV/P04
Ayqs~&{
public void setSFileName(String value) x zF
{ IO8 @u;&
sFileName = value; 6*S/frE
} z,m3U(
(EWGX |QA
O*?^a7Z)4
public int getNSplitter() +,)k@OI
{ sgK =eBE
return nSplitter; FO_}9<s
} We}9'X}
,#,K_oz
oowofi(E
public void setNSplitter(int nCount) J0R{|]W8
{ N-F&=u}
nSplitter = nCount; k}<H
} diM*jN#
} H9TeMY
e> 9X
CUpRtE8@[_
/* zsQkI@)sO
**Utility.java 2RNee@!JJP
*/ L9Zz-Dr s
package NetFox; 5TuwXz1v
m ne)c[Qn
x<!]#**;
public class Utility { -wC}JVVcK
Wll0mtv
iY@}Q "
public Utility() vS5}OV
{ l 7dm@S
_$IWr)8f
b&h'>(
} oupWzjo
cOpe6H6,bz
//线程睡眠 Z P|k3
public static void sleep(int nSecond) 3)=ix. wW
{ BWYv.&=(
try{ JiXE{(
Thread.sleep(nSecond); Q Rr9|p{
} N@<-R<s^
catch(Exception e) O!dS;p-F
{ >ZPu$=[W
e.printStackTrace (); Jg'#IM
} V!]|u ^4I
} W!XBuk-
.0U[nt6
//日志 5X];?(VTsb
public static void log(String sMsg) K-Pcew^?
{ A~E S{Zkh
System.err.println(sMsg); M8Bp-_
} & }j;SK5
rBL2A
S\I+UeFkf
public static void log(int sMsg) 'NjeF&#6
{ PEjd
System.err.println(sMsg); pl,XS6mB
} p%bMfi*T
} It/'R-H
IpzU=+h
|p*cI @
/* XHgW9;M!
**TestMethod.java _hJ+8B^`
*/ N&k\X]U
package NetFox; o\Fv~^
ZWuNl!l>
uInI{>
public class TestMethod { 3My}u>
#H~$^L
Xs$a^zZ
public TestMethod() K9ih(fh)
{ ///xx/weblogic60b2_win.exe e9:pS WA-n
try{ -3d`e2^&}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?@MY+r_G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P$h) Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); Fpn'0&~-fi
fileFetch.start(); ?AxB0d9z
} O<>+l*bk
catch(Exception e){e.printStackTrace ();} 69ycP(
8>vNa
W>{&" 5
} %O[1yZh \
kMEXgzl
5?(dI9A"K
public static void main(String[] args) 9"B;o
{ ,_7m<(/f
new TestMethod(); I)*J,hs1
} Z!'kN\z
} qOyS8tA.H
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