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)); ccwz:7r
} g4&f2D5
for(int i=0;i<nEndPos.length-1;i++) FXh*!%"*
{ SS!b`
nEndPos = nStartPos[i+1]; iM M s3
} ?\_vqW
nEndPos[nEndPos.length-1] = nFileLength; lY[\eQ 1:
} Qb8Z+7
} o]@'R<F(u
?G 'sb}.
K&BaGrR
//启动子线程 R{UZCFZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5V8`-yO9
for(int i=0;i<nStartPos.length;i++) cp2a @
{ *0x!C8*`Xe
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =55V<VI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2hY"bpGW
nStartPos,nEndPos,i); k_`YVsEYP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lw_@(E]E
fileSplitterFetch.start(); aj]pN,g@N
} KN'twPFq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \0.!al0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 't+'rG6x
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =Y*zF>#lP
nEndPos = " + nFileLength); 5h6-aQU[
// fileSplitterFetch[nPos.length-1].start(); \?[m%$A
i4lB]k
&n]]OPo
//等待子线程结束 g=jB'h?
//int count = 0; '#lc?Y(pJ2
//是否结束while循环 pER[^LH_)
boolean breakWhile = false; MUUhg
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m O"Rq5
while(!bStop) =yZ6$ hK
{ y=zs6HaS
write_nPos(); "qoJIwl#q
Utility.sleep(500); <`Qbb=*
breakWhile = true; aB{OXU}#
3j2d&*0
8i Ew;I_
for(int i=0;i<nStartPos.length;i++) wcW7k(+0
{ s){R/2O3F
if(!fileSplitterFetch.bDownOver) q+ka}@
{ )kIjZ
breakWhile = false; nPhREn!
break; {7.uwIW.1
} c=aVYQ"2
} ,.AXQ#~&`
if(breakWhile) >nO[5
break; 1rV9dM#F
7pM&))R
]CX^!n
//count++; -qG7,t
//if(count>4) 1;HL=F
// siteStop(); 2]}e4@{
} Ct]? /
/w2NO9Q
F41gMg
System.err.println("文件下载结束！"); 4%7Oaf>9
} rEoOv
catch(Exception e){e.printStackTrace ();} 0yxwsBLy
} @B9#Hrc
w:2yFC
]W7&ZpF
//获得文件长度 O@>{%u
public long getFileSize() at(gem
{ (I;lE*>
int nFileLength = -1; A_+*b [P
try{ R)Dh;XA
URL url = new URL(siteInfoBean.getSSiteURL()); o<rbC < U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JqtOoR
httpConnection.setRequestProperty("User-Agent","NetFox"); orhzeOi\
i}@5<&J
FYH^axpp
int responseCode=httpConnection.getResponseCode(); ;Bat--K7+
if(responseCode>=400) v1$}JX
{ :<uCi\9(
processErrorCode(responseCode); d.k'\1o
return -2; //-2 represent access is error j6Au<P
} /UtSZ(
).jna`A,
qot{#tk d
String sHeader; Vu,:rPqI
:AyZe7:(D
?uXY6J"
for(int i=1;;i++) Z|j\_VKhl
{ p7[&H/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a KIS%M#Y
//Utility.log(in.readLine()); 2>.>q9J(
sHeader=httpConnection.getHeaderFieldKey(i); l#a*w
if(sHeader!=null) 4g?qKoc i
{ ,&jjpeZP
if(sHeader.equals("Content-Length")) }R`}Ey|{
{ '8b=4mrbH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QY$4D;M`g6
break; ^?T,>ZI
} sNJ?Z"5k1h
} PcvA/W
else F2v9XMi
break; \$ :)Ka
} .&/A!3pW
} f0g&=k{OD
catch(IOException e){e.printStackTrace ();} \8`^QgV`@
catch(Exception e){e.printStackTrace ();} EI@ep~
kv`5"pa7M
$B`bsJ
Utility.log(nFileLength); )T@+"Pw8t
SpZmwa #\
g$mqAz<
return nFileLength; [}y"rs`!
} kLbo |p"cT
h|ja67VG
\?AA:U*
//保存下载信息（文件指针位置） kaVYe)~
private void write_nPos() v[>8<z8
{ K\$z,}0
try{ r`C t/]c
output = new DataOutputStream(new FileOutputStream(tmpFile)); sE0,b
output.writeInt(nStartPos.length); O9Yk5b;
for(int i=0;i<nStartPos.length;i++) ? \NT'CG
{ E9j(%kQ2
// output.writeLong(nPos); eb<'>a
output.writeLong(fileSplitterFetch.nStartPos); g=s2t"&
output.writeLong(fileSplitterFetch.nEndPos); X($@E!|
} ,@t#)HV
output.close(); (ce"ED`1
} =[o/D0-Kn
catch(IOException e){e.printStackTrace ();} 0*o=JM]
catch(Exception e){e.printStackTrace ();} 'Y5=A!*@tf
} a0Q\]S
CvqUaHW@
KQ.cd]6
//读取保存的下载信息（文件指针位置） IFWP&20
private void read_nPos() ~<[]l~`
{ O9F#gO|!
try{ Y+"Gx;F>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JDBNi+t
int nCount = input.readInt(); }fz;La:b
nStartPos = new long[nCount]; *1_A$14l
nEndPos = new long[nCount]; XPcx"zv\
for(int i=0;i<nStartPos.length;i++) 5<?/M<i
{ ]BBjFs4#
nStartPos = input.readLong(); ]yA_N>k2K
nEndPos = input.readLong(); ^Xslj
} SMh[7lU`
input.close(); }Yp]A
} =JB1]b{|
catch(IOException e){e.printStackTrace ();} }pv<<7}|
catch(Exception e){e.printStackTrace ();} U KdCG.E9^
} jI807g+
cin3)lm
CB?,[#r5f
private void processErrorCode(int nErrorCode) ,T7(!)dR
{ b=Y3O
System.err.println("Error Code : " + nErrorCode); )nUTux0K\
} Y--Uo|H
U`ELd:
D~%h3HM
//停止文件下载 _xU2C<)1&
public void siteStop() :@+@vM;gh
{ 0G/_"}@
bStop = true; )9>E} SU/
for(int i=0;i<nStartPos.length;i++) )rv<"
fileSplitterFetch.splitterStop(); 84maX'
k'+Mc%pg4E
PiwI.c
} !:Clzlg
} Q GDfX_
//负责部分文件的抓取 kM/;R)3t4/
**FileSplitterFetch.java ;923^*\:F{
*/ >zB0+l
package NetFox; b `.h+=3
JV9Ft,xk
X.!|#FWb+
import java.io.*; XxE>KeP
import java.net.*; n7K\\|X
+W9#^
L\X2Olfz1
public class FileSplitterFetch extends Thread { 8p~G)J3U
D[}qhDlX
VcR(9~
String sURL; //File URL M]OZS\9.B
long nStartPos; //File Snippet Start Position 4f> s2I&pQ
long nEndPos; //File Snippet End Position %q 7gl;'
int nThreadID; //Thread's ID n+uDg
boolean bDownOver = false; //Downing is over h^"OC$
boolean bStop = false; //Stop identical ?BnjtefIe
FileAccessI fileAccessI = null; //File Access interface :0B' b
[\e2 ID;
|\ 4cQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B":u5_B
{ &c1zEgl
this.sURL = sURL; :u>9H{a
this.nStartPos = nStart; \d{S3\7
this.nEndPos = nEnd; >D/+04w
nThreadID = id; VtD:'L-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q@/358.LA
} `.a~G y
H:M;H=0
xu7Q^F#u
public void run() Acib<Mi2!-
{ 5 MD=o7O^
while(nStartPos < nEndPos && !bStop) x(/{]$h
{ u|]`gsFZ\
%t\~3pw=
}H<87zH
try{ |v%xOl
URL url = new URL(sURL); +=A53V[C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EAM2t|MG.
httpConnection.setRequestProperty("User-Agent","NetFox"); YX:[],FP
String sProperty = "bytes="+nStartPos+"-"; !o&b:7
httpConnection.setRequestProperty("RANGE",sProperty); $'>h7].
Utility.log(sProperty); "FT(U{^7d
JgY#W1>
:Pf2oQ
InputStream input = httpConnection.getInputStream(); &*wc` U
//logResponseHead(httpConnection); Zm!5X9^!
csay\Q{
byUstm6y
byte[] b = new byte[1024]; B)4>:j:{?W
int nRead; VaRP+J}UA.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N/&t)7
{ Zl+Ba
nStartPos += fileAccessI.write(b,0,nRead); {Jj vF
//if(nThreadID == 1) G(1y_t
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |SF5'\d'
} dLnMd0
9!sR}
O}IRM|r"
Utility.log("Thread " + nThreadID + " is over!"); V,CVMbn/%N
bDownOver = true; IDpW5Dc
//nPos = fileAccessI.write (b,0,nRead); }\Mmp+<
} >'X[*:Cx
catch(Exception e){e.printStackTrace ();} 60 z =bd]
} <c&6M
} / !*+9+h
ir ^XZVR
wNgS0{}&`
//打印回应的头信息 *N#{~
public void logResponseHead(HttpURLConnection con) k)l^;x-
{ oH|<(8efD
for(int i=1;;i++) .;xt{kK
{ AH#eoKu
String header=con.getHeaderFieldKey(i); =whYo?cE(
if(header!=null) cc^[u+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y=)xo7(
Utility.log(header+" : "+con.getHeaderField(header)); NJ{M-K%>
else b];p/V# <
break; $M=W`E[g
} nmZJ%n
} 8Ekk"h6
PHh&@:
:"oQ _bLT
public void splitterStop() xi =\]
{ ^ |^Q(
bStop = true; =,-&h V
} ]wQ#8}zO
BL^8gtdn
Uj[E_4h
} |Vs?yW
<8Zm}-U
i!JVGs
/* CF:s@Z+
**FileAccess.java |#. J
*//文件访问(定位，写) j%qBNoT~
package NetFox; #,KjJ
import java.io.*; 71# ipZ
DVWqrK}q
"/zIsn7
public class FileAccessI implements Serializable{ =#"ZO
`bdCom
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?U`~,oI0
RandomAccessFile oSavedFile; RN%*3{-
long nPos; UpU2H4
R}-<ZJe
+W6QtB6
public FileAccessI() throws IOException ]EhW
{ VkNg Vjg
this("",0); };:+0k/
} MZ{gU>K+
_8U 5mW
u,R;=DNl
public FileAccessI(String sName,long nPos) throws IOException z[I3k
{ f/Lyc=-]
oSavedFile = new RandomAccessFile(sName,"rw"); mXH\z
this.nPos = nPos; q)ns ui(
oSavedFile.seek(nPos); jd]YKaI
} @,Iyn<v{B
`bJ+r)+5
& bwhD.:=
public synchronized int write(byte[] b,int nStart,int nLen) ; SS/bS|
{ 8"zFTP*;u
int n = -1; d,_Ky#K5b
try{ n!r<\4I
oSavedFile.write(b,nStart,nLen); _U"9#<
n = nLen; Whd2mKwiO
} H7xyK
catch(IOException e) $#k8xb
{ /8(\AuDT
e.printStackTrace (); QyGTm"9l
} &C.{7ZNt
8~=<!(M)m/
'TF5CNX
return n; 02lI-xHe
} !`rR;5&sT
^rmcyy8;g
'V=i;2mB*
} .FarKW
l1&NU'WW
;w/|5 ;{A;
/* NT^m.o~4
**SiteInfoBean.java ._uXK[c7P
*/ "lFS{7
package NetFox; ^11y8[[
_dgS@n;6
5ir[}I^z
public class SiteInfoBean { P,|%7'?Y
8+>r!)Q+
5u<F0$qHc
private String sSiteURL; //Site's URL [=})^t?8
private String sFilePath; //Saved File's Path ;PO{ ips
private String sFileName; //Saved File's Name c==5cMUg
private int nSplitter; //Count of Splited Downloading File ne=?'e4
_NfdJ=[Xh
\lJCBb+k
public SiteInfoBean() /YP,Wfd%
{//nSplitter的缺省值为5 zT\nj&7
//default value of nSplitter is 5 [p+]H?(A
this("","","",5); [IF5Iv\b
} Pp*:rA"N
< )dqv0=
]Kutuf$t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y;X_E7U
{ m5wfQ_}}ss
sSiteURL= sURL; o_.f7|U!
sFilePath = sPath; Z#O )0ou
sFileName = sName; ps DY}y\"
this.nSplitter = nSpiltter; \; 9log<Z
J<"=c z$
)(?,1>k`Z
} jvI!BZ
M@k8;_5
l@ amAusE
public String getSSiteURL() &tNnW
{ )Vn(J#s
return sSiteURL; }de{-
} 4jOq.j
X 5.%e&`
1Mftq4nq
public void setSSiteURL(String value) DLigpid
{ "Je*70LG#
sSiteURL = value; fEdp^oVg
} eSqKXmH[m
Bb,l.w
3Kx&+
public String getSFilePath() =bx;TV
{ tJ"8"T#6Vr
return sFilePath; 6aw1
} zS9HR1
FO"sE`
Qj1qx;S
public void setSFilePath(String value) Jv,*rQH
{ ^\ N@qL
sFilePath = value; 9+"R}Nxv^
} ~`xaBz0q
gMGX)Y ,=/
]^e4coC
public String getSFileName() cYC@@?
{ qG]G0|f
return sFileName; \aEarIX#*
} AHo4% 5
?M}W;Z
M$jU-;hRH
public void setSFileName(String value) _d[4EY
{ _Q**4
sFileName = value; q =\3jd
} &>@
hT=6XO od4
:t7M'BSm2z
public int getNSplitter() K P1;u#v
{ ?tA<:.<vtY
return nSplitter; ;R_H8vp
} U_&v|2o#3
> [%ITqA$
T{USzMj
public void setNSplitter(int nCount) R_vF$X'Ow
{ \l_U+d,qq
nSplitter = nCount; j(QK0"z
} fn~Jc~[G|
} m,Fug1+N
F['<;}
nlq"OzcH04
/* Izapx\GK9
**Utility.java Rv/=bY
*/ $:RP tG
package NetFox; RT`jWWh*Lo
x%Fy1.
'm4v)w<y#
public class Utility { ~+~^c|
\FL`b{!+ N
gG,"wzj
public Utility() ndXUR4
{ RT~6#Caf
MYlPG1X=?
8fH.E
} 2Hp<(
A.v'ws+VDP
//线程睡眠 Fv )H;1V
public static void sleep(int nSecond) o6v'`p'
{ #cAX9LV
try{ evLZ<|
Thread.sleep(nSecond); 0dKv%X#\
} 7`G FtX}
catch(Exception e) UNC%<=
{ ju8DmC5
e.printStackTrace (); x\R%hGt
} 7rZE7+%]
} (QFu``ae+
"Yy)&zKr
//日志 sT<XZLu
public static void log(String sMsg) :&'[#%h8
{ <CIy|&J6
System.err.println(sMsg); @((Y[<
} mC,:.d
2Sha&Z*CE
{ ML)F]]
public static void log(int sMsg) 1M<;}hJ{/
{ ^h5h kIx0
System.err.println(sMsg); 'ZXd|WI
} )_H>d<di
} -Z<V?SFOK
xV+cX*4h
qQ/<\6Sl
/* *@-a{T}
**TestMethod.java AnD#k]
*/ VS\+"TPuH
package NetFox; l.Yq4qW
C"[d bh!
]T<\d-!CZN
public class TestMethod { OV+|j
\:pd+8
Vgg'5o&.
public TestMethod() G,,7.%eib=
{ ///xx/weblogic60b2_win.exe _C&XwCIm
try{ }%lk$g';
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~1g)4g~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ysDGF@wZC
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4^uwZ:
fileFetch.start(); 0V!@*Z
} } >zl
catch(Exception e){e.printStackTrace ();} &XF@Dvv
hha!uD~(
U3rpmml
} 47yzI-1H+
MWHzrqCA
C<"b99\2`
public static void main(String[] args) FS^ie|8{D-
{ {Hr P;)
new TestMethod(); !IAd.<,
} j#D( </T
} zLS=>iLD{
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