http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); `2hLs _
} ;!,I1{`
for(int i=0;i<nEndPos.length-1;i++) .Z(Q7j^
{ (N?nOOQ
nEndPos = nStartPos[i+1]; u]sxX")
} EL(BXJrx{
nEndPos[nEndPos.length-1] = nFileLength; .\mkgAlyaM
} o,[Em<
} ~mC>G 4y$a
Dn:1Mtj-
z LZHVvL3
//启动子线程 ?$.x%G+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cf%aOHYI*
for(int i=0;i<nStartPos.length;i++) E'^ny4gL
{ 8u7QF4 Id
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <['ucp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d"OYq
nStartPos,nEndPos,i); 3hfv^H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5,9cD`WR^
fileSplitterFetch.start(); \]0+J
} =}'7}0M_=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2?kVbF
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D*t[5,~j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 58t~? 2E
nEndPos = " + nFileLength); h(p cGE
// fileSplitterFetch[nPos.length-1].start(); A@jBn6
#@m6ag.
J+l#!gk$!
//等待子线程结束 &Xh=bM'/%m
//int count = 0; lw_@(E]E
//是否结束while循环 aj]pN,g@N
boolean breakWhile = false; KN'twPFq
\0.!al0
't+'rG6x
while(!bStop) h>ZU67-
{ =\)76xC20
write_nPos(); \?[m%$A
Utility.sleep(500); i4lB]k
breakWhile = true; >OKc\m2%Q
<.:mp1,8V
<vd}oiB@
for(int i=0;i<nStartPos.length;i++) 85BB{T;
{ }c=YiH,o
if(!fileSplitterFetch.bDownOver) ??z&w`Yy,
{ ]0=THq\H
breakWhile = false; sNZOm$
break; R0e!b+MZ.
} 3{M0iNc1
} .p%V]Ka
if(breakWhile) O)c3Lm-w
break; o.wXaS8
WF-^pfRq~
I].ddR%
//count++; 7>f)pfLM
//if(count>4) &/?OP)N,}
// siteStop(); BiA^]h/|
} K0\`0E^,
r{wf;5d(
BC R]K
System.err.println("文件下载结束！"); qdo_YPG
} !'Ww%ZL\
catch(Exception e){e.printStackTrace ();} .J?RaH{i
} A>6_h1
Awe'MGp%
x\pygzQ/
//获得文件长度 :=\`P
public long getFileSize() ihD|e&
{ '![VA8
int nFileLength = -1; G0(A~Q"
try{ e}ivvs2
URL url = new URL(siteInfoBean.getSSiteURL()); $]MOAj"LH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H[N~)3x
httpConnection.setRequestProperty("User-Agent","NetFox"); cFHSMRB|P
vj"['6Xa
KN~Repcz@
int responseCode=httpConnection.getResponseCode(); uFL!*#A
if(responseCode>=400) xP &@|Ag
{ W?0u_F
processErrorCode(responseCode); Hk?E0.
return -2; //-2 represent access is error y1#QP3'Z1
} o<rbC < U
`+(4t4@ew
7e /Kh)5G
String sHeader; 1-Q>[Uz,
G{0f* cH)
!J(6E:,b#
for(int i=1;;i++) u?KG%
{ +f,I$&d.V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tDtqTB}
//Utility.log(in.readLine()); Qm4cuV-0{
sHeader=httpConnection.getHeaderFieldKey(i); 5Zl7crA[
if(sHeader!=null) z5W;-sCz
{ J7k=5Fqej;
if(sHeader.equals("Content-Length")) zwK$ q=-:
{ Tx(=4ALY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7eG@)5Uy
break; c+jnQM'
} i}>}%l|
} @}{Fw;,(7n
else ._<gc;G
break; 9mEhZ"
} qG0gc\C}
} c3Zwp%
catch(IOException e){e.printStackTrace ();} RY*yj&?w[
catch(Exception e){e.printStackTrace ();} e r"gPW
cBU@853
d4o_/[
Utility.log(nFileLength); L>!MEMqm
1wW4bg 5
X:W}S/
return nFileLength; r]&&*:
} EC?U#!kv
BXr._y, cr
!={QL:
//保存下载信息（文件指针位置） ]%UAN_T
private void write_nPos() n yNHjn |W
{ jyC>~}?
try{ sVP2$?
output = new DataOutputStream(new FileOutputStream(tmpFile)); M \>5",0
output.writeInt(nStartPos.length); `7'=~BP?X
for(int i=0;i<nStartPos.length;i++) dfs1BV'
{ Dm`gzGl
// output.writeLong(nPos); J=ot&%
output.writeLong(fileSplitterFetch.nStartPos); D66!C{
output.writeLong(fileSplitterFetch.nEndPos); rm,h\
} `(8RK
output.close(); K\$z,}0
} )`zfDio-1V
catch(IOException e){e.printStackTrace ();} ||.Ve,<:
catch(Exception e){e.printStackTrace ();} ;o.,vQF*
} >u=nGeO
"H}ae7@
#DcK{|ty
//读取保存的下载信息（文件指针位置） cQh=Mri]
private void read_nPos() s$VLVT*6
{ op|x~Thf
try{ qGie~S ##
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y |Tv;v1L
int nCount = input.readInt(); s4>xh=PoJ
nStartPos = new long[nCount]; Yq:TWeZD
nEndPos = new long[nCount]; e{0O"Jd`
for(int i=0;i<nStartPos.length;i++) RueL~$*6.~
{ m\ /V0V\
nStartPos = input.readLong(); \>4x7mF!
nEndPos = input.readLong(); WI54xu1M
} *JVJKqed
input.close(); 6 i]B8Ziq{
} #^q@ra
catch(IOException e){e.printStackTrace ();} b!g8NG
catch(Exception e){e.printStackTrace ();} sUsIu,1Q
} V_pKe~
5@~5RNrq2
LU@+O12
private void processErrorCode(int nErrorCode) RTTEAh:.
{ 'w}/o+x@
System.err.println("Error Code : " + nErrorCode); znd fIt^
} '8fL)Zk
,YmTx
)X-TJ+d
//停止文件下载 mOx>p"n
public void siteStop() ~ *P9_<
{ U6oab9C?k
bStop = true; }ABHGr5[
for(int i=0;i<nStartPos.length;i++) xiQ;lE
fileSplitterFetch.splitterStop(); tNCKL.yU
i- r y5x
GK:pt8=
} U`ELd:
} D~%h3HM
//负责部分文件的抓取 pw1&WP&?3
**FileSplitterFetch.java (+0yZ7AZ
*/ wGnFDkCNz
package NetFox; u/L\e.4
lF!Iu.MM 9
-44''w?z
import java.io.*; !u|s|6{\
import java.net.*; Sc&p*G
@KC;"u'C
Q GDfX_
public class FileSplitterFetch extends Thread { T13Jno
;923^*\:F{
>zB0+l
String sURL; //File URL b `.h+=3
long nStartPos; //File Snippet Start Position JV9Ft,xk
long nEndPos; //File Snippet End Position '} LAZQ"
int nThreadID; //Thread's ID !Ql&Ls
boolean bDownOver = false; //Downing is over )F4P-u
boolean bStop = false; //Stop identical 6B>H75S+H
FileAccessI fileAccessI = null; //File Access interface /h73'"SpDy
JD$;6Jv3P
W=T,hOyh<W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QOY M/1U
{ 8&9'1X5)8_
this.sURL = sURL; ;yg9{"O
this.nStartPos = nStart; 7 {#^zr
this.nEndPos = nEnd; Tof H=d
nThreadID = id; NI?YUhg>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p=8?hI/bim
} $WK~|+"{>
~gvw6e*[
z8hAZ?r1`
public void run() :HG5{zP
{ mmrz:_
while(nStartPos < nEndPos && !bStop) >vY5%%}
{ :u>9H{a
\d{S3\7
Lj03Mx.2S
try{ VtD:'L-
URL url = new URL(sURL); 6,;7iA]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FrryZe=
httpConnection.setRequestProperty("User-Agent","NetFox"); H:M;H=0
String sProperty = "bytes="+nStartPos+"-"; xu7Q^F#u
httpConnection.setRequestProperty("RANGE",sProperty); S?Z"){
Utility.log(sProperty); vS'5Lm
p-o!K\o-1
L5yv}:.U
InputStream input = httpConnection.getInputStream(); iSxuor^;
//logResponseHead(httpConnection); o2M4?}TpIV
Y:}!W
|VD}:
byte[] b = new byte[1024]; )$e_CJ}9e
int nRead; vL"[7'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fbK`A?5K
{ ON<X1eU
nStartPos += fileAccessI.write(b,0,nRead); OAXF=V F#
//if(nThreadID == 1) s0x;<si_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #y&O5
} L@HWm;aN
Sx3R2-!Z
Qcf5*]V
Utility.log("Thread " + nThreadID + " is over!"); )j>BvO
bDownOver = true; <i!7f26r
//nPos = fileAccessI.write (b,0,nRead); CA{(x(W\:
} COf>H0^%Q
catch(Exception e){e.printStackTrace ();} nJ-U*yz
} x#_0 6
} [Vaw$c-+[y
6:vdo~
Xm!;
//打印回应的头信息 Iib39?D W
public void logResponseHead(HttpURLConnection con) i5 F9*
{ R87e"m/C%
for(int i=1;;i++) g x~fZOF_
{ I,xV&j+<
String header=con.getHeaderFieldKey(i); 2E":6:Wsw
if(header!=null) m@){@i2.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <ny)yK
Utility.log(header+" : "+con.getHeaderField(header)); eDPmUlC+-
else Gv3AJ'NL
break; `<:D.9vO "
} 5<y pK`Kq
} I6E!$}
!DUC#)F
evBr{oi@
public void splitterStop() z;VabOr^
{ >C|i^4ppI
bStop = true; P@z,[,sy"$
} W;Ei>~E
c _v;"QZ
RIO4`,
} }}'0r2S
]FLi^}ct
{b6$F[e
/* ^1^muc[
**FileAccess.java eBW=bK~[VP
*//文件访问(定位，写) !w9w{dtW=
package NetFox; ?A4t &4
import java.io.*; `Mxi2Y{vp
]wQ#8}zO
d]*a:>58
public class FileAccessI implements Serializable{ ZRd,V~iz
V@"Y"}4n4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Dqw?3 KB
RandomAccessFile oSavedFile; Z/S7ei@56
long nPos; VTt{0 ~
QP{V
+=/FKzT<
public FileAccessI() throws IOException WI$MT6
{ ,9C~%c0Pw
this("",0); C<.Ny,U
} "/zIsn7
=#"ZO
pGO)9?j_N
public FileAccessI(String sName,long nPos) throws IOException viJK%^U=-
{ wA#w]8SM
oSavedFile = new RandomAccessFile(sName,"rw"); 1[;~>t@C
this.nPos = nPos; -3fzDxD
oSavedFile.seek(nPos); ]8qFxJ+2^
} eBmBD"$
hZobFf
G-)Q*p{i|
public synchronized int write(byte[] b,int nStart,int nLen) %;r0,lN|II
{ AGe\PCn-
int n = -1; a\Ond#1p
try{ d}.*hgk
oSavedFile.write(b,nStart,nLen); jxU z-U-
n = nLen; l?N|Gj;ZFZ
} A#y,B
catch(IOException e) ;L gxL Qy;
{ sr&hQ
e.printStackTrace (); f;nO$h[Qb
} DhAQ|SdCf
K; +w'/{
6jKZ.S+s)
return n; GuV.7&!x
} ,y+}0q-Ou
X7*i-v@
VqeK~,}
} J^J$I!
U;7Cmti"
M%evk4_27
/* ]R$ u3F
**SiteInfoBean.java I+?9}t
*/ #xMl<
package NetFox; />Z`?
avb'J^}f
BP6|^Q
public class SiteInfoBean { [LQD]#
LtxeT.
vt`V<3
private String sSiteURL; //Site's URL cF[L6{Oe
private String sFilePath; //Saved File's Path FC:+[.fi
private String sFileName; //Saved File's Name DRn]>IFU
private int nSplitter; //Count of Splited Downloading File IwfJDJJ
8<Y*@1*j
W?n)IBj8
public SiteInfoBean() .@3
{//nSplitter的缺省值为5 z)RJUmY3B
//default value of nSplitter is 5 JFyw,p&xB
this("","","",5); {*Ag[HS0u
} Gd:TM]rJ
H+oQ L(i|_
t4RI%m\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &.zG?e.
{ 't+ J7
sSiteURL= sURL; g/o@,_
sFilePath = sPath; `FjU2 O
sFileName = sName; J 8z|ua
this.nSplitter = nSpiltter; #^+C kHX
A{HP*x~t
oV)#s!
} fL #e4
R|jt mI?
s+@+<QE
public String getSSiteURL() m0I)_R#X[
{ |L@&plyB-
return sSiteURL; 00?_10x)
} aDV~T24
)Oxsasn)M
K/Q%tr1W0
public void setSSiteURL(String value) >tmv3_<=
{ A)2eo<ij4
sSiteURL = value; Ej\Me
} k$kOp *X
4@iMGYR9!s
=N62 ){{
public String getSFilePath() e ej:
{ lo1<t<w`
return sFilePath; D#=$? {w
} }#u.Of`6"
b6`_;Z
!CBvFl/v
public void setSFilePath(String value) Oy,7>vWQI
{ H2ZRUFu
sFilePath = value; ;qA(!`h+
} Lp|7s8?
<|!?V"`3
pk%%}tP<
public String getSFileName() [tKH'}/s=
{ q X"Pg
return sFileName; qhdY<[6
} FZt a
d@$]/=%
/IO<TF(X
public void setSFileName(String value) \]j{
{ o9<)rUy
sFileName = value; ,P%a0\
} {Wi)/B}
>/r^l)`9_f
Oc Gg'R7
public int getNSplitter() mMNT.a
{ ~t>i+{JKE
return nSplitter; 'n>v}__&|
} sjZ@}Vk3b
gB3Tz(!
ii3{HJ*C
public void setNSplitter(int nCount) \ah.@s
{ $QNII+o
nSplitter = nCount; (~6D`g`B
} W~!uSrY
} lYF~CNvE
W Ai91K@
d)R7#HLZ7
/* CeZ+!-lG
**Utility.java Y"n$d0%
*/ 1edeV48{:
package NetFox; IO@Ti(,
0SHF 8kek
6h5,XcO4
public class Utility { +Fk]hCL
{:63% j
iI]E%H}
public Utility() mRECdGst
{ 6EX_IDb
;8~tt I
<Z>p1S
} Fk-}2_=vi
'm4v)w<y#
//线程睡眠 JZUf-0q
public static void sleep(int nSecond) !4/s|b9K
{ Ag82tDL[u
try{ fF|m~#y
Thread.sleep(nSecond); f4[Bj{F
} !W4X4@
catch(Exception e) dsUt[z1w5
{ k"L?("~
e.printStackTrace (); ZLS\K/F>>=
} M>yt\qbkA
} %3@a|#g
|Ok=aV7
//日志 oIJ.Tv@N(
public static void log(String sMsg) < %t$0'
{ V6CRl&ZKO
System.err.println(sMsg); &^I2NpT
} \7d T]VV
$q%l)]+
hmG^l4B.T
public static void log(int sMsg) 7rZE7+%]
{ (QFu``ae+
System.err.println(sMsg); "Yy)&zKr
} 4#fgUlV
} }vXf}2C
R#\o*Ta
k^:+Pp
/* &~ .n}h&
**TestMethod.java ?j:g.a+U
*/ 9EU0R H
package NetFox; s6YnNJ,SK
{Rv0@)P$
XZew$Om[
public class TestMethod { *;0Ods+IcY
+FGw)>g8'm
5/f"dX
public TestMethod() gNj~o^6|@
{ ///xx/weblogic60b2_win.exe <`P7^ 'z!
try{ z7PmyU >
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VS\+"TPuH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l.Yq4qW
SiteFileFetch fileFetch = new SiteFileFetch(bean); C"[d bh!
fileFetch.start(); ]T<\d-!CZN
} ;&~9k?v7L
catch(Exception e){e.printStackTrace ();} tDQo1,(oY
z"PU`v
<AN=@`+
} C U 8s*
: 6|nXL
j +u3VP
public static void main(String[] args) O,Sqh$6U
{ 7&>==|gt
new TestMethod(); Tz<@k
} _]"uq/UWp
} q Xj]O3 mm
点击下载更多相关资料