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)); mV,R0olF
} ^aXBt
for(int i=0;i<nEndPos.length-1;i++) ZhsZywM
{ "b 0cj
nEndPos = nStartPos[i+1]; aJ8pJ{,P
} rg,63r
nEndPos[nEndPos.length-1] = nFileLength; >v[(w1?rX
} 9HX+sB M
} A-5+#
+&OqJAu
!qlGt)G3
//启动子线程 {0 ~0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c*dww
for(int i=0;i<nStartPos.length;i++) 9#<Og>t2y
{ Gq*)]X{Ua
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j;)g+9`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YJ$ewK4E#.
nStartPos,nEndPos,i); B5:g{,C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F-^HN%
fileSplitterFetch.start(); `VtwKt*
} -`OR6jd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0>iFXw:fn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d8HB2c5y0i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }&DB5M
nEndPos = " + nFileLength); Jj:6 c
// fileSplitterFetch[nPos.length-1].start(); \w^QHX1+
FRFAWK<
au|^V^m
//等待子线程结束 It4z9Gh
//int count = 0; U$)Hhn|X
//是否结束while循环 C8EC?fSQ
boolean breakWhile = false; N;'HR)
s.`d<(X?
T3./V0]\I
while(!bStop) G%!\ p:w
{ y.p6%E_`
write_nPos(); fm%RNAPvc
Utility.sleep(500); SFk#bh
breakWhile = true; Jv<$AI
N?;o_^C
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for(int i=0;i<nStartPos.length;i++) 7[g;|(G0
{ jJ!-hg4?]
if(!fileSplitterFetch.bDownOver) ).C!
{ {X<4wxeTo
breakWhile = false; xn@0pL3B~
break; *ldMr{s<R
} ]M;6o@hq
} q9Sz7_K
if(breakWhile) .vS6_
break; 1?|6odc
b$O_L4CP
JA(fam~{
//count++; RX5.bVp eE
//if(count>4) UZP6x2:=
// siteStop(); _i[)$EgFm
} -'[(Uzj
`QdQ?9x{F
rAWl0y_m
System.err.println("文件下载结束！"); +RV-VrV
} xwnoZ&h
catch(Exception e){e.printStackTrace ();} #we>75l{+R
} _]xt65TL
oL'1Gm@X?
.3<IOtD=
//获得文件长度 H:-A; f!Z
public long getFileSize() oNB,.:
{ ?[VpN2*
int nFileLength = -1; ej%;%`C-
try{ $[iT~B$
URL url = new URL(siteInfoBean.getSSiteURL()); ]A72)1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <;cE/W}}
httpConnection.setRequestProperty("User-Agent","NetFox"); =HY1l}\
@f{_=~+
rEyz|k:
int responseCode=httpConnection.getResponseCode(); ncattp
if(responseCode>=400) s)YP%vn#
{ zLQ#GF
processErrorCode(responseCode); u:$x6/t
return -2; //-2 represent access is error C`n9/[,#
} i*CQor6|z
F|l`YtZZd
=6L*!JP<
String sHeader; +K%pxuVh
OR\DTLIl
pEVgJ/>
for(int i=1;;i++) D!}K)T1~R
{ /.)[9bQ<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -~\.n
//Utility.log(in.readLine()); .S!>9X,
sHeader=httpConnection.getHeaderFieldKey(i); 5m^Hi}S_
if(sHeader!=null) a-5HIY5
{ "f|(@a
if(sHeader.equals("Content-Length")) >u5g?yzw
{ 58&{5YpS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qX{X4b$
break; ?#m<\]S<
} AL]h|)6QpC
} *el(+ib%
else oWDSK^
break; /*AJr
} -/UXd4S
} R+E_#lP_$
catch(IOException e){e.printStackTrace ();} tyuk{*Me:
catch(Exception e){e.printStackTrace ();} 3gG+`{<
"65||[=8
LMFK3Gd[
Utility.log(nFileLength); >H}jR[H'
OyJsz]b} M
.3a:n\tY
return nFileLength; HX3D*2v":
} ],\sRQbv&
^r>f2 x
O:;OR'N9
//保存下载信息（文件指针位置） ^p 2.UW
private void write_nPos() g={]Mzh
{ 2"leUur~rO
try{ 1Sg|3T8bGT
output = new DataOutputStream(new FileOutputStream(tmpFile)); G;C8Kde
output.writeInt(nStartPos.length); {jOzap|
for(int i=0;i<nStartPos.length;i++) T2DF'f3A
{ j?\$G.Y
// output.writeLong(nPos); gT(th9'+z
output.writeLong(fileSplitterFetch.nStartPos); JG@L5f
output.writeLong(fileSplitterFetch.nEndPos); "($Lx
} 9jO`gWxV8*
output.close(); 6[*;M
} 4[TS4p
catch(IOException e){e.printStackTrace ();} %'L].+$t
catch(Exception e){e.printStackTrace ();} djsz!$
} K/vxzHSl
Q`S iV
V(;55ycr
//读取保存的下载信息（文件指针位置） ofMu3$Q
private void read_nPos() ZD5I5
{ uw Kh
try{ 7~wFU*P1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5zNSEI"PY
int nCount = input.readInt(); }+Rgx@XZ\
nStartPos = new long[nCount]; s, n^
nEndPos = new long[nCount]; EkJVFHfh
for(int i=0;i<nStartPos.length;i++) *wC\w
{ /"""z=q
nStartPos = input.readLong(); 2J;kD2"!
nEndPos = input.readLong(); tYs8)\{
} .P)s4rQ\
input.close(); t_jyyHxoZ:
} N[qA2+e$Z
catch(IOException e){e.printStackTrace ();} vG]GQ#
catch(Exception e){e.printStackTrace ();} x37/cu
} _urG_~q
c ]>DI&$;J
LH=d[3Y
private void processErrorCode(int nErrorCode) lSH ZV Fd
{ XkPv*%Er8
System.err.println("Error Code : " + nErrorCode); XC|*A$x,
} )v%l0_z{
F:M>z=
6xH;:B)d
//停止文件下载 X=v~^8M7%
public void siteStop() &Nc[$H7<
{ )@}A r
bStop = true; }m6f^fs}
for(int i=0;i<nStartPos.length;i++) ?gLR<d_
fileSplitterFetch.splitterStop(); [IiwNqZ[~
In f9wq\
9s! 2 wwh
} /~40rXH2C
} vO\:vp4fH
//负责部分文件的抓取 t]s94 R q
**FileSplitterFetch.java ~?#~Ar
*/ 8r,9OM
package NetFox; }>2t&+v+
gaQ[3g
NW z9C=y
import java.io.*; N0+hejz
import java.net.*; Da-u-_~
B@-|b
A9 U5,mOz
public class FileSplitterFetch extends Thread { k+FMZ,D|
Le*`r2
p-.Ri^p
String sURL; //File URL NX?}{'f
long nStartPos; //File Snippet Start Position 5XDgs|8
long nEndPos; //File Snippet End Position 8tU>DJ}0
int nThreadID; //Thread's ID mge#YV::
boolean bDownOver = false; //Downing is over n_v02vFAHT
boolean bStop = false; //Stop identical hM?`x(P
FileAccessI fileAccessI = null; //File Access interface i8K_vo2Z)
'|Qd0,Z
_B)s=Snx
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 2Kjrw;
{ o&~dGG4J
this.sURL = sURL; ;;:">@5
this.nStartPos = nStart; |2O')3p"9
this.nEndPos = nEnd; vX ?aB!nkw
nThreadID = id; _=pWG^a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S+r^B?a<oM
} 0!pJ5q ,A
wfE^Sb3
7%e1cI
public void run() nE_Cuc>K\
{ oz LH]*
while(nStartPos < nEndPos && !bStop) eNtf#Rqym
{ ]DO&x+Rb
e,(a6X
Oukd_Ryf
try{ :$NsR*Cq*9
URL url = new URL(sURL); 1Pm4.C)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V\0E=M*P
httpConnection.setRequestProperty("User-Agent","NetFox"); jgG$'|s}
String sProperty = "bytes="+nStartPos+"-"; u^t$cLIZ
httpConnection.setRequestProperty("RANGE",sProperty); c&E]E(
Utility.log(sProperty); g0PT8]8
Xx_tpC?
Qlw>+y-i
InputStream input = httpConnection.getInputStream(); 9TC) w|
//logResponseHead(httpConnection); 58::h.:
~(P&g7u
09'oz*v{#
byte[] b = new byte[1024]; uQnT[\k?
int nRead; H9U.lb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %)?`{O~ h
{ @Gt`Ds9=
nStartPos += fileAccessI.write(b,0,nRead); V@[rf<,
//if(nThreadID == 1) &=X.*H%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |jsb@
} uAUp5XP|Z
S`0NPGn;@[
dN< ,%}R
Utility.log("Thread " + nThreadID + " is over!"); $E\^v^LW
bDownOver = true; >TY6O.]
//nPos = fileAccessI.write (b,0,nRead); \8e2?(@"k
} L_~8"I_
catch(Exception e){e.printStackTrace ();} (-,>qMQs
} DSvmVI
} yI&9\fn
>{wuEPA
U6<M/>RG$
//打印回应的头信息 Huc|6~X
public void logResponseHead(HttpURLConnection con) )hBE11,PB
{ cLG6(<L
for(int i=1;;i++) BgM%+b8u
{ -}P7$|O&
String header=con.getHeaderFieldKey(i); ]W/>Ldv
if(header!=null) 9gy(IRGq/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); le8 #Z}p
Utility.log(header+" : "+con.getHeaderField(header)); 2Q@Y^t
else y\D=Z N@
break; <.bRf
} 1Ipfw
} Xh F_]
D<>@ %"%
y!~qbh[
public void splitterStop() Be2lMC
{ p$Hi[upy
bStop = true; | &7S8Q
} H;Ku w
t0Mx!p'T
wP<07t[-g
} z=g$Exl
pvF-Y9Xb
vcv CD7MD
/* BhkoSkr
**FileAccess.java [ *>AN7W
*//文件访问(定位，写) [c~kF+8
package NetFox; uOd&XW
import java.io.*; K\u_Ji]k
y t5H oy
XKS8K4"
public class FileAccessI implements Serializable{ 2'] KTHm
Dvc&RG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e2cP *J
RandomAccessFile oSavedFile; 5)UQWnd5
long nPos; ;wHCj$q
l1'6cLT`
3I $>uR
public FileAccessI() throws IOException 9t$]X>}
{ bm#(?
this("",0); AXPMnbUS
} ~Lz%.a;o
/?*]lH.
q%i-`S]}qL
public FileAccessI(String sName,long nPos) throws IOException cBXWfv4
{ G8J*Wnwu[K
oSavedFile = new RandomAccessFile(sName,"rw"); %JyXbv3m,
this.nPos = nPos; {<=#*qx[Y!
oSavedFile.seek(nPos); />44]A<
} ,|h)bg7.
2VGg 6%
U*)m',
public synchronized int write(byte[] b,int nStart,int nLen) oD.r`]k
{ _S`o1^Ad
int n = -1; CU)|-*uiK
try{ j Ux z
oSavedFile.write(b,nStart,nLen); :O= \<t
n = nLen; eE@&ze>X
} }4//@J?:
catch(IOException e) g(|{')8?d
{ T~4N+fK
e.printStackTrace (); Qk1xUE
} OLC{iD#
&ldBv_
8|%^3O 0X
return n; ,|kDsR!
} 6#@ f'~s
])}(k
cC'x6\a
} n$n7-7
r^,<(pbd
x[3A+
/* nh>K`+>co
**SiteInfoBean.java cV{o?3<:B
*/ F4L;BjnJ
package NetFox; o*rQP!8,oy
x1&W^~
6CbxuzYer
public class SiteInfoBean { pmWr]G3,*
-E"GX
/X'(3'a
private String sSiteURL; //Site's URL G 2!xPHz
private String sFilePath; //Saved File's Path fw6UhG
private String sFileName; //Saved File's Name ^= 0m-/
private int nSplitter; //Count of Splited Downloading File ]X Z-o>+,
%zk$}}ti.
Y!J>U
public SiteInfoBean() ?>"Yr,b?
{//nSplitter的缺省值为5 #~O b)q|
//default value of nSplitter is 5 0tg8~H3yy
this("","","",5); kn"(mJe$
} ]n."<qxeT
::FS/Y]Fg
:>Rv!x`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <Z}SKR"U%
{ XxIHoX&
sSiteURL= sURL; /,=@8k!t?
sFilePath = sPath; { FZ=olZ
sFileName = sName; 3psU?8(
this.nSplitter = nSpiltter; 3I\n_V<
7\FXz'hA
V-'K6mn;
} G)v #+4
W6H,6v
l<0}l^C.
public String getSSiteURL() X4l@woh%
{ ';Zi@f"
return sSiteURL; ~vlype3/EF
} |waIpB(
K*UgX(xu4P
W"^wnGa@a
public void setSSiteURL(String value) a<}#HfC;'
{ ]0hrRA`
sSiteURL = value; Mj[f~
} B(xN Gs
>{\7&}gz
)XcOl7XLN
public String getSFilePath() %NL^WG:
{ ;bHV
return sFilePath; ^j-3av=
} !aO` AC=5u
^WBuMCe
Z87_#5
public void setSFilePath(String value) w?kJ+lmOQy
{ dT,o=8fg
sFilePath = value; "BX!
} {ZY+L;eg1
P) 3mX.(}
.`>y@p!
public String getSFileName() J{^RkGF
{ E4m`
return sFileName; ,|&9M^
} A\8}|r(>9E
K2%w0ohC
P(F+f`T
public void setSFileName(String value) |$5[(6T|
{ #9K-7je;j
sFileName = value; a7N!B'y
} 3Zi@A4Wu
da)NK!
-B86U6^s
public int getNSplitter() @v}/zS
{ V5*OA??k<
return nSplitter; \=_{na_
} B&D}F=U
^Q+g({
EkziAON
public void setNSplitter(int nCount) jH_JmYd
{ fbUr`~Y"
nSplitter = nCount; 7jdb)l\p=
} As>_J=8} 3
} ?lP':'P
9K1oZ?)_z
%2v4<icvq
/* ,\NFt`]j
**Utility.java y*X_T,K8
*/ \L"kV!>
package NetFox; )ZN|t?|
qvPtyc^fN
Z?\>JM >;
public class Utility { B ~OZ2-~
720DV+o
R?]02Q
public Utility() '3uVkp 6tF
{ 8@tV9+u
kh`"WN Nt
6i}iAP|0
} s_mS^`P7
yj\Nkh
//线程睡眠 c"[cNZo
public static void sleep(int nSecond) %$b:X5$Z
{ z*-2.}&U<
try{ A{A\RSZ0
Thread.sleep(nSecond); ?!+MM&c-n
} P'_H/r/#
catch(Exception e) 0\eIQp
{ wp&=$Aa)'
e.printStackTrace (); ?"g!
} @ta7"6p-i@
} 13>0OKg`#
Y=Kc'x[,Zj
//日志 "men
public static void log(String sMsg) &G-!qxe
{ .X;3,D[w
System.err.println(sMsg); /{&tY:;m
} MjU6/pO}L
_ jsK}- \
.hifsB~
public static void log(int sMsg) Om5Y|v"*
{ cI4K+
System.err.println(sMsg); w 47tgPPk
} n^g|Ja
} (=om,g}
_WRFsDZ'
B\XKw'
/* sc}~8T
**TestMethod.java Sn|BlXrey
*/ X<I+&Zi
package NetFox; X"fb;sGT
5;YMqUkw
Ck)*&
public class TestMethod { H*r)Z90
4GX-ma,
B\o Mn
public TestMethod() }n>p4W"OM
{ ///xx/weblogic60b2_win.exe H["`Mn7j2
try{ MB~=f[cUnd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A|<jX}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C@'h<[v`1v
SiteFileFetch fileFetch = new SiteFileFetch(bean); N u<_}
fileFetch.start(); $adbCY\
} 6V7B;tB
catch(Exception e){e.printStackTrace ();} )!P)U(*v
:qd`zG3
JPoN&BTCj
} 5?]hd*8
T9Nb`sbV]
K/|Z$4S
public static void main(String[] args) A\HxDIU
{ `ojoOB^L
new TestMethod(); u=`L)
} aWR}R>E
} (KDD e}f
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