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)); LP~$7a
} Rq7ksTo
for(int i=0;i<nEndPos.length-1;i++) 4c% :?H@2
{ C{))T5G
nEndPos = nStartPos[i+1]; =mZw71,
} DXUI/C f
nEndPos[nEndPos.length-1] = nFileLength; c2C8}XJ|O
} 86_Zh5:
} rT#QA=YB
Q,$x6YwE
;i]cmy
//启动子线程 R Q8okA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rLnu\X=h$
for(int i=0;i<nStartPos.length;i++) /~yqZD<O
{ ";~#epPkX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c"~TH.,d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3FdoADe{{
nStartPos,nEndPos,i); ZG>OT@ GA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4MIVlg9
fileSplitterFetch.start(); Np<Aak
} ^Z!W3q Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |J\/U,nh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B}(YD;7vJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FD*y[A ?
nEndPos = " + nFileLength); >Cf`F{X'U
// fileSplitterFetch[nPos.length-1].start(); Jx}5`{\
Xy{b(b;9
SbZk{lWcq
//等待子线程结束 |qr[*c3$1
//int count = 0; ~`BOzP
//是否结束while循环 6Z"%vrH
boolean breakWhile = false; +)|2$$m
{p-%\nOC
X;1q1X)K
while(!bStop) ;2iZX=P`n
{ TnG"_VK9R
write_nPos(); vfjIpg%i
Utility.sleep(500); L?P8/]DGp
breakWhile = true; UYPBKf]A9
MMf6QxYf
\DHCf4,
for(int i=0;i<nStartPos.length;i++) =nsY[ s<
{ <7p2OPD
if(!fileSplitterFetch.bDownOver) \yy!?UlaI
{ YZk&'w
breakWhile = false; rf~Ss<
break; h<j04fj
} _CZ*z
} t5_`q(:
if(breakWhile) ;?&;I!
break; 'W#<8eJo
l]ZUKy
Z(.Tl M2h
//count++; d/^^8XUK
//if(count>4) VTHDGBU
// siteStop(); -or9!:8
} R%Z} JR.
wOsr#t7
[9L(4F20
System.err.println("文件下载结束！"); Q.fBuF
} ^_oLhNoez2
catch(Exception e){e.printStackTrace ();} ;A C] *
} LJ)3!Q/:
bcZuV5F&
`i{:mio
//获得文件长度 Bj2rA.M
public long getFileSize() ?{[H+hzz0
{ 6!'yU=Z`
int nFileLength = -1; :eO]65N
try{ }}]Y mf
URL url = new URL(siteInfoBean.getSSiteURL()); P8EGd}2{8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mZ5UaSG
httpConnection.setRequestProperty("User-Agent","NetFox"); rS jC/O&b
ug{F?LW[
)uaB^L1
int responseCode=httpConnection.getResponseCode(); ux }DWrR
if(responseCode>=400) dlU=k9N-
{ UX0tI0.tg
processErrorCode(responseCode); 936t6K&
return -2; //-2 represent access is error gK>Vm9rO
} ~}5(J,1!
wHCsEp(
ufo?ZFq@$L
String sHeader; 'ZJ6p0
u+V;r)J{
<(iOzn
for(int i=1;;i++) #:yZJS9f9
{ nO/5X>A,Zw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (tz! "K
//Utility.log(in.readLine()); kju:/kYA
sHeader=httpConnection.getHeaderFieldKey(i); MhsG9q_%
if(sHeader!=null) 3aOFpCs|#
{ oM VJ+#[x
if(sHeader.equals("Content-Length")) k.0C*3'
{ (u_sz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )CB?gW
break; u-W=~EO5#
} $D89|sy
} HaSH0eTw
else &>/nYvuq-
break; 3S9~rLrn?
} 8}0 D?
} "~ `-Jkm
catch(IOException e){e.printStackTrace ();} fG{oi(T
catch(Exception e){e.printStackTrace ();} 07#!b~N
:Y'nye3:
p[wjHfIq
Utility.log(nFileLength); 3ty){#:
5|b/G
w.3R1}R
return nFileLength; \<8!b{F
} #=tWCxf=
Z\Q7#dl
@Q^;qMy
//保存下载信息（文件指针位置） @4|/| !
private void write_nPos() pr?/rXw
{ "gO5dZ\0
try{ f6#H@ X
output = new DataOutputStream(new FileOutputStream(tmpFile)); p<jr&zVEc>
output.writeInt(nStartPos.length); UOu&sg*o2B
for(int i=0;i<nStartPos.length;i++) OU+*@2")t
{ J0K"WmW
// output.writeLong(nPos); H0HYb\TX?
output.writeLong(fileSplitterFetch.nStartPos); 1Y`MJ\9
output.writeLong(fileSplitterFetch.nEndPos); Ob+&!XTp?0
} 9f@)EKBK
output.close(); vuAjAeKm
} /?GBp[(0
catch(IOException e){e.printStackTrace ();} G pd:k
catch(Exception e){e.printStackTrace ();} ;CW$/^QNr5
} )Ga6O2:
|j+~Td3})&
ieI-_]|[
//读取保存的下载信息（文件指针位置） YU`{
private void read_nPos() YszhoHYh
{ :Ls36E8f=
try{ &td#m"wI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EAfSbK3z
int nCount = input.readInt(); u|ZO"t
nStartPos = new long[nCount]; {)y4Qp
nEndPos = new long[nCount]; _H,RcpyJ
for(int i=0;i<nStartPos.length;i++) )t4C*+9<U
{ phdN9<Z
nStartPos = input.readLong(); c1^3lgPv
nEndPos = input.readLong(); p c],H
} $CmTsnR1#y
input.close(); (07d0<<[
} #&Ee5xM=
catch(IOException e){e.printStackTrace ();} ,Tx8^|b#F
catch(Exception e){e.printStackTrace ();} K+\hv~+@
} Ixw,$%-]y6
;1%a:#5
)&9RoW()?
private void processErrorCode(int nErrorCode) .EdV36$n
{ _=MWt_A '3
System.err.println("Error Code : " + nErrorCode); H,}?YW
} wB^a1=C
I?"5i8E
9V&LJhDQ
//停止文件下载 N9Ml&*%oX{
public void siteStop() Ua]zTMI
{ sF$m?/Kt
bStop = true; D4\I;M^
for(int i=0;i<nStartPos.length;i++) ]Oy<zU
fileSplitterFetch.splitterStop(); -O5m@rwt<
KkY22_{ac
R4/@dA0
} Ir'f((8:
} (0+m&, z
//负责部分文件的抓取 a|NU)mgEI
**FileSplitterFetch.java iCS/~[
*/ H]e 2d|
package NetFox; riL!]'akV
|#wz)=mD
0 Yp;?p^
import java.io.*; A@ME7^w7
import java.net.*; D\R^*k@V
sn(}5;
N;HvB:c
public class FileSplitterFetch extends Thread { Ce:ds%
0u_'(Z-^2
gUp0RPs
String sURL; //File URL `Nn?G
long nStartPos; //File Snippet Start Position 7r>W r#
long nEndPos; //File Snippet End Position DFonK{
int nThreadID; //Thread's ID Zux2VepT
boolean bDownOver = false; //Downing is over U~m.I
boolean bStop = false; //Stop identical zMKL: Um"
FileAccessI fileAccessI = null; //File Access interface #7=LI\
St`m52V(5X
YLGLr@:q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q)>'fZ)
{ H<;j&\$q
this.sURL = sURL; yH^*Fp8V
this.nStartPos = nStart; -+>am?
this.nEndPos = nEnd; ui1m+
nThreadID = id; RHbwq]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bed+Ur&
} t3G'x1
UZra'+Wb
$w\, ."y
public void run() In&vh9Lw
{ m##=iB|;
while(nStartPos < nEndPos && !bStop) 9:o3JGHSc
{ B*IDx`^Y
H[ q{R
;^]A@WN6_
try{ =HHg:"
URL url = new URL(sURL); Ne 4*MwK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v%5(-
httpConnection.setRequestProperty("User-Agent","NetFox"); (#]KjpIK
String sProperty = "bytes="+nStartPos+"-"; 3)Y:c2
httpConnection.setRequestProperty("RANGE",sProperty); <.ky1aex7
Utility.log(sProperty); Dfia=1A
Fev3CV$
T#7^6Ks+1
InputStream input = httpConnection.getInputStream(); L ]c9
//logResponseHead(httpConnection); S)yV51^B
]||=<!^kn
mI#; pO2
byte[] b = new byte[1024]; ]6 wi
int nRead; !`lqWO_/ :
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T*yveo&j
{ 3G^Ed)JvE
nStartPos += fileAccessI.write(b,0,nRead); *.g?y6d
//if(nThreadID == 1) dL(|Y{4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R:N-y."La.
} +ctv]'P_
[[Z>(d$8
`x)bw
Utility.log("Thread " + nThreadID + " is over!"); sdQv:nd'R
bDownOver = true; 1#"Q' ,7
//nPos = fileAccessI.write (b,0,nRead); JB@VP{
} W?-BT >#s
catch(Exception e){e.printStackTrace ();} "M^W:4_
} J-F_XKqH
} kB#vh
"6Uj:9
+;;%Atgn
//打印回应的头信息 }8 _9V|E
public void logResponseHead(HttpURLConnection con) J_|x^
{ (B<AK4G
for(int i=1;;i++) KTt$Pt/.
{ 79H+~1Az
String header=con.getHeaderFieldKey(i); (14kR
if(header!=null) ;NE/!!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &Q>'U6"%
Utility.log(header+" : "+con.getHeaderField(header)); nD\os[ 3
else T0%TeFY
break; J|S^K kC
} 2j1v.%
} 3ohcHQ/a
r:4IKuTR
E2'e}RQ
public void splitterStop() Tj5@OcA$
{ J5_Y\@
bStop = true; N'P,QiR,z<
} .+}o'rU
!!%[JR)cS
Wy*7jB
} kTWg31]~
vqMk)htIz
5KE%@,k k
/* :iB%JY Ad
**FileAccess.java k^c=y<I
*//文件访问(定位，写) :b*`hWnQ
package NetFox; Z[u,1l.T
import java.io.*; fMPq
Q0Qm0B5eY
Mk/!,N<h#
public class FileAccessI implements Serializable{ `sy &dyM
)=nPM`Jn.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !r obau7
RandomAccessFile oSavedFile; E(kpK5h{
long nPos; SoU'r]k1x
<<5 :zlb
^@L l(?
public FileAccessI() throws IOException (Zg'pSs)
{ y6jmn1K
this("",0); gzCMJ<3!D
} I S8nvx\
u;ooDIq@
Bye@5D
public FileAccessI(String sName,long nPos) throws IOException }"B? 8T@_~
{ tW"ptU^9)
oSavedFile = new RandomAccessFile(sName,"rw"); 1idjX"'
this.nPos = nPos; CU1\C*
oSavedFile.seek(nPos); }_(^/pnk
} iz>y u[|
.L5*E(<K0
G4%M$LJh
public synchronized int write(byte[] b,int nStart,int nLen) m4SXH> o
{ :#:O(K1PW
int n = -1; pUMB)(<k
try{ w+q;dc8
oSavedFile.write(b,nStart,nLen); agm5D/H]:
n = nLen; 0!,gT H>
} &xuwke:[
catch(IOException e) 6Y_O^f
{ -b\V(@5
e.printStackTrace (); 3p 1EScH
} 6(^Upk=59
)):22}I#
GHC?Tp
return n; (<R\
} |5B,cB_
FWpN:|X BS
4:eq{n
} *tfDXQ^mN
1;kG[z=A
&#PBww
/* pY!dG-;
**SiteInfoBean.java |8qK%n f}
*/ u~- fK'/!|
package NetFox; QB3d7e)8>
Prb_/B Dd
t#pqXY/;D
public class SiteInfoBean { eIUuq&(
i=X*
w^rb|mKo
private String sSiteURL; //Site's URL |;U=YRi
private String sFilePath; //Saved File's Path M`+e'vdw
private String sFileName; //Saved File's Name k CW!m
private int nSplitter; //Count of Splited Downloading File gUH'DS]{
RnA&-\|*
Bw]L2=d
public SiteInfoBean() 9p\Hx#^
{//nSplitter的缺省值为5 MHnf\|DX
//default value of nSplitter is 5 5 2@udp
this("","","",5); mj~N]cxB
} (\mulj
#S53u?JV8
xngeV_xc2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N{V5 D
{ bg1"v a#2
sSiteURL= sURL; 1;Wkt9]9
sFilePath = sPath; ()nKug`.@
sFileName = sName; j*H;a ?Y
this.nSplitter = nSpiltter; \5_P5q:`
h%1~v$W`
FJd8s*
} A|taP$%
{GQ Aa
8>VI$
public String getSSiteURL() [Zt# c C+
{ >^H'ZYzw
return sSiteURL; Cwsoz
} Ck3QrfM
=|gJb|?w
3Zaq#uA
public void setSSiteURL(String value) N0K>lL=
{ cbh#E)['
sSiteURL = value; o,CA;_
} iFnOl*TC
Iu-'o
gY>;|),
public String getSFilePath() 65waq~#
{ uP(B<NfL:'
return sFilePath; zr3q>]oma
} cZaF f?]k
A{4G@k+#d
Mm5U`mB
public void setSFilePath(String value) ~}$\B^z+
{ )RA\kZ"
sFilePath = value; 2Ft8dfdm`
} k(-Z@
CQBT::
C7b 5%a!
public String getSFileName() 95$pG/o
{ 6^]`-4*W
return sFileName; @Xq&t}*8
} "M9TB. O
V~J*49t&2J
l$qStL*8O
public void setSFileName(String value) YeRcf`
{ .K|P&
sFileName = value; BN\fv,
} i>tW|N
~']&.
a9D gy_!Y
public int getNSplitter() VMxYZkMNd_
{ C!ZI&cD9
return nSplitter; tp1KP/2w[
} (XbMrPKG
FylWbQU9
hF7V !*5
public void setNSplitter(int nCount) G}=`VYK
{ CdBthOPX)
nSplitter = nCount; Wj&<"Z6'm(
} k_*XJ<S!Y
} VO.-.
b?Cmc
2!{_/@I\Y
/* 'GV&]
**Utility.java ER~T'-YMS
*/ E6'8Zb
package NetFox; 3AdP^B<
x1 ;rb8
&5kZ{,-eM
public class Utility { @9_nwf~X4
q4sl=`L5Sp
lSn5=^]q
public Utility() ~a'nHy1
{ lq>*x=<
eZ@Gu
O%YjWb
} @DfkGm[%
vQ:x%=]
//线程睡眠 S}zC3
public static void sleep(int nSecond) 8lU;y)Z
{ -d|BO[4j
try{ SW,q}-
Thread.sleep(nSecond); Hi]vHG(
} ojN`#%X
catch(Exception e) ?@Z7O.u
{ <KHv|)ak
e.printStackTrace (); #'J~Xk
} Qy{NS.T
} wD<vg3e[H
]~?S~l%
//日志 5"1!p3`\D{
public static void log(String sMsg) /yx=7<
{ CCuxC9i7
System.err.println(sMsg); Rz`@N`U
} v\fzO#vj
gXq!a|eH
kk 8R
public static void log(int sMsg) t*o7,
{ r> Fec
System.err.println(sMsg); Xy[}Gp
} Z -pyFK\
} jmRhAJV
kjx>
c*.G]nRc
/* D",A$(lG
**TestMethod.java xM%H~(
*/ hX0RET
package NetFox; G+ :bL S#:
2#'rk'X,K
VKT@2HjNT`
public class TestMethod { V)2"l"Kt
+7Sf8tg\
&\&'L|0F
public TestMethod() GMEw
{ ///xx/weblogic60b2_win.exe `ifb<T
try{ v]66.-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $TR=3[j
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Bp&6x;MJf
SiteFileFetch fileFetch = new SiteFileFetch(bean); zXQVUhL6
fileFetch.start(); 1T!cc%ah
} j?=VtVP
catch(Exception e){e.printStackTrace ();} 5_v5
)qbI{^_g
~af8p {
} 1lbwJVY[
qO7fbql_
+VwV5iy[`
public static void main(String[] args) h{\t*U54'
{ W|lH
new TestMethod(); o(:{InpV%A
} a4%`"
} )y6QAp
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