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)); [i`
} 4GRD- f[
for(int i=0;i<nEndPos.length-1;i++) HU $"o6ap
{ ;o!p9MEpz;
nEndPos = nStartPos[i+1]; CJ\a7=*i
} |#@7$#j
nEndPos[nEndPos.length-1] = nFileLength; U=.PL\
} G;l7,1;MU:
} zl@^[km{
2h
J,yKO(}<C
//启动子线程 (`.OS)&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XP@dg4Z=z
for(int i=0;i<nStartPos.length;i++) ,Z@#( =f
{ R+M=)Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g#J aw|N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 35& ^spb
nStartPos,nEndPos,i); a{]=BY oL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \X8b!41
fileSplitterFetch.start(); vFVUdxPOw
} zFq%[X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !4vb{AH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fHup&|.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4!/JN J
nEndPos = " + nFileLength); UphTMyn3
// fileSplitterFetch[nPos.length-1].start(); <kK>C8+
7AV{ h[J
2tq2
//等待子线程结束 =Z^5'h~
//int count = 0; Y@+Rb
//是否结束while循环 zqeQ
boolean breakWhile = false; j>\c >U
r<UVO$N
G)Gp}4gV}
while(!bStop) _uQ]I^'D
{ 1INX#qTZ
write_nPos(); z'q~%1t
Utility.sleep(500); n%&L&G
breakWhile = true; Ay16/7h@hi
p R'J4~
IOl_J>D]F
for(int i=0;i<nStartPos.length;i++) X.fVbePxUU
{ n[3z_QI
if(!fileSplitterFetch.bDownOver) Qg*\aa94
{ U**8^:*y#:
breakWhile = false; "6f`hy
break; /f3/}x!po
} {@InOo!4w]
} ^[?y 2A:
if(breakWhile) -tg|y
break; p;+O/'/j
N[I@}j
kTb$lLG\xk
//count++; UBaXS_c\
//if(count>4) ku]5sd >b
// siteStop(); cc[(w #K
} ipv5JD[
=w$&n%~
3B1\-ry1M
System.err.println("文件下载结束！"); pDR~SxBXr
} {"ST hTZ
catch(Exception e){e.printStackTrace ();} )eyzHB,H
} U]3!"+Y1P
hd)Jq'MCS
54_}9_g
//获得文件长度 }'oU/@yG
public long getFileSize() Z.\q$U7'9
{ ;I>nA6A
int nFileLength = -1; NHd@s#@
try{ KL&/Yt
URL url = new URL(siteInfoBean.getSSiteURL()); ")Fd'&58
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?@b6(f xX
httpConnection.setRequestProperty("User-Agent","NetFox"); >yO/p(/;jR
vzIo2,/7
S<nF>JRJa
int responseCode=httpConnection.getResponseCode(); l/N<'T_G
if(responseCode>=400) ZJ/528Ju
{ ?v2_7x&
processErrorCode(responseCode); /q9I^ztV
return -2; //-2 represent access is error A,~3oQV
} 5|H;%T3_
V!Wy[u
UleT9 [M
String sHeader; Tv``\<
!nBbt?*
k~tEUsv
for(int i=1;;i++) 4Q|>k)H
{ WcN4ff-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :aNjh
//Utility.log(in.readLine()); |bnd92fvks
sHeader=httpConnection.getHeaderFieldKey(i); ]v ${k
if(sHeader!=null) 8+'}`
{ ;(NTzBq!1
if(sHeader.equals("Content-Length")) Z0<Vss
{ kF|$oBQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PL:(Se%
break; '.Y,VJaL
} >dAl*T
} IK -vcG
else S@qPf0dL<
break; K"!rj.Da
} &f.5:u%{b
} @@Q4{o
catch(IOException e){e.printStackTrace ();} zIc6L3w$
catch(Exception e){e.printStackTrace ();} DsdM:u*s
6r~9$IM
b^W&-Hh
Utility.log(nFileLength); w~]2c{\Qz
P27Ot1px
C @Ts\);^
return nFileLength; 3qWrSziD
} }i+C)VUX
(qAF2&
db )2>
//保存下载信息（文件指针位置） 2Io|?
private void write_nPos() :|j[{;asY
{ ~?/7:S
try{ DI0& _,
output = new DataOutputStream(new FileOutputStream(tmpFile)); aCU[9Xr?
output.writeInt(nStartPos.length); PF4[;ES'
for(int i=0;i<nStartPos.length;i++) UynGG@P@
{ A;Uc&G
// output.writeLong(nPos); QYA4C1h'
output.writeLong(fileSplitterFetch.nStartPos); QytO0K5
output.writeLong(fileSplitterFetch.nEndPos); ?1\5X<|,
} k5RzW4zq;
output.close(); ( fFrX_K]
} |gk*{3~y
catch(IOException e){e.printStackTrace ();} |.; N_i
catch(Exception e){e.printStackTrace ();} ?qQ{]_q1&.
} 3U6QYD55]]
LW=qX%o{
=9&2udV1
//读取保存的下载信息（文件指针位置） JQ+Mg&&Q
private void read_nPos() 48p3m)5
{ KDN#CU
try{ L4iWR/&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); whI4@#
int nCount = input.readInt(); R&uPoY,f
nStartPos = new long[nCount]; 7] y3<t
nEndPos = new long[nCount]; /qQx~doK
for(int i=0;i<nStartPos.length;i++) |6AR!
{ icG 9x
nStartPos = input.readLong(); P}6#s'07~
nEndPos = input.readLong(); ZRhk2DA#FF
} )=)N9CRy
input.close(); &^ERaPynd
} B} qRz
catch(IOException e){e.printStackTrace ();} (CQ! &Z8
catch(Exception e){e.printStackTrace ();} m]DP{-s4
} kV8R.Baf3
3n2^;b/]
Q}&'1J
private void processErrorCode(int nErrorCode) RrLiH>
{ 8mr fs%_
System.err.println("Error Code : " + nErrorCode); 6Emn@Mn=
} uNf'Zeo
Nr@,In|JS
za6 hyd^
//停止文件下载 R655@|RT
public void siteStop() R/{h4/+vJ
{ .3EEi3z6z
bStop = true; 3g7]$}
for(int i=0;i<nStartPos.length;i++) 1=]#=)+
fileSplitterFetch.splitterStop(); $bp'b<jx
D u<P^CE
~Dg:siw
} @.e4~qz\
} 42`Uq[5Y
//负责部分文件的抓取 iu{y.}?
**FileSplitterFetch.java @G&oUhS
*/ `y'%dY}$n
package NetFox; 3B#fnj
jzi%[c<G
*r>Y]VG;S
import java.io.*; 1drg5
import java.net.*; K`=U5vG^
#W:.Fsq
~U<j_j)z4.
public class FileSplitterFetch extends Thread { s\.r3U&6
2zo>`;l
c%<81Y=
String sURL; //File URL S*r }oX0
long nStartPos; //File Snippet Start Position ~,W|i
long nEndPos; //File Snippet End Position tT`S" 9T
int nThreadID; //Thread's ID aaVq>$G3
boolean bDownOver = false; //Downing is over .WglLUJ:Z
boolean bStop = false; //Stop identical L<
FileAccessI fileAccessI = null; //File Access interface "P5,p"k:)
.==c~>N
`~axOp9N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @>`N%wH'
{ ,-])[u
this.sURL = sURL; OfLj 4H6Q
this.nStartPos = nStart; 6T"5,Q</h
this.nEndPos = nEnd; FkaQVT
nThreadID = id; )m-(-I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z){fie4WM
} iLdUus!
g9GPyU
=j_4!^
public void run() !rx5i
{ p+I`xyk
while(nStartPos < nEndPos && !bStop) :t;\`gQoS
{ 6/a%%1c1
w&U28"i>
:hHKm|1FE
try{ UeUOGf ,
URL url = new URL(sURL); Na\&}GSf^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jcePSps]
httpConnection.setRequestProperty("User-Agent","NetFox"); "97sH_ ,
String sProperty = "bytes="+nStartPos+"-"; f`}u9!jVR
httpConnection.setRequestProperty("RANGE",sProperty); jp-(n z\
Utility.log(sProperty); QIwO _[Q
USE!
GWx?RIKF
InputStream input = httpConnection.getInputStream(); eT F s9$
//logResponseHead(httpConnection); H1evW
45+kwo0
MNfc1I_#
byte[] b = new byte[1024]; V(G{_>>
int nRead; [CnoMN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @ /e{-Q
{ 8v)Z/R-
nStartPos += fileAccessI.write(b,0,nRead); kaZcYuT.9
//if(nThreadID == 1) gYL#} )g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DUf. F
} %z1hXh#+
^]LWcJ?"^!
CIR2sr0a
Utility.log("Thread " + nThreadID + " is over!"); h#h)=;
bDownOver = true; ud(w0eX
//nPos = fileAccessI.write (b,0,nRead); enMHKN g
} Zf)<)o*
catch(Exception e){e.printStackTrace ();} >wV2` 6
} ++kVq$9@y
} O|;|7fCB\
6%VRQ#g!
]xJ2;{JWsO
//打印回应的头信息 J@Nq
public void logResponseHead(HttpURLConnection con) K>+c2;t;
{ En+`ZcA\z
for(int i=1;;i++) }g.)%Bw!
{ ovtZHq/
String header=con.getHeaderFieldKey(i); cMUmJH
if(header!=null) Xt*h2&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V=GP_^F
Utility.log(header+" : "+con.getHeaderField(header)); )=h+5Z>E1
else g*U[?I"sC
break; (Sj?BZjC
} _t7aOH
} -A8CW9|mk
~:A=o?V2
~RM_c
public void splitterStop() xqKj&RuLu
{ [MM`#!K%
bStop = true; uY)|
} JOq&(AZe
0bIhP,4&
grCz@i
} yzCamm4~0
o 3 G*
:2&W9v
/* ma2-66M~j
**FileAccess.java _nW#Cl~
*//文件访问(定位，写) r/ LgmVRn
package NetFox; \g;-q9g;O
import java.io.*; c(S66lp
>x1?t
[1`&\C_E
public class FileAccessI implements Serializable{ 4q^'MZm1
DmpD`^?-L
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yFqB2(Dv
RandomAccessFile oSavedFile; GA)t!Xg^
long nPos; , rc %#eF
>^KO5N-:4
*p%=u>?&
public FileAccessI() throws IOException 8DJoQl9
{ pj'[ H
this("",0); =I9RM9O<
} 7pz #%Hf
sZPA(N?
FAd4p9[Y
public FileAccessI(String sName,long nPos) throws IOException }7|UA%xz
{ lxD~[e
oSavedFile = new RandomAccessFile(sName,"rw"); LZ*ZXFIg
this.nPos = nPos; 64-;| k4F
oSavedFile.seek(nPos); w ]$Hr
} h>'Mh;+
6<C|O-
_QOZ`st
public synchronized int write(byte[] b,int nStart,int nLen) nx'D&,VX
{ -]~vEfq+T
int n = -1; *U^7MU0
try{ Wi{ jC?2Q
oSavedFile.write(b,nStart,nLen); EJ`"npU
n = nLen; wtnC^d$
} Bgj^n{9x
catch(IOException e) <MBpV^Y}
{ -eoXaP{[
e.printStackTrace (); a{7'qmN1
} V17SJSC-
$4&e{fLt|v
x.~AvJ
return n; 5QUL-*t
} .:=G=v=1
.+ g8zbD4
mXXU{IwUe
} |.Y}2>{
"_ i:
)>|x2q
/* jUCrj'
**SiteInfoBean.java hUGP3ExC*
*/ }&O}t{gS*
package NetFox; S4FR=QuVQC
W #kOcw
R<n'v.~"A
public class SiteInfoBean { xF8^#J6>
1MnT*w
jou741
private String sSiteURL; //Site's URL m3E`kW|
private String sFilePath; //Saved File's Path Wc qUF"A
private String sFileName; //Saved File's Name +Q+>{HK
private int nSplitter; //Count of Splited Downloading File wXnluE
y)e8pPDG
]3iQpL
public SiteInfoBean() i917d@r(<
{//nSplitter的缺省值为5 zBTyRL l
//default value of nSplitter is 5 I[v6Y^{q
this("","","",5); &;]KntxB
} R-V4Ju[:
vhOX1'
K/Qo~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9d_ Zdc
{ f,}9~r#
sSiteURL= sURL; X1PXX!]lo[
sFilePath = sPath; oF0BBs$
sFileName = sName; p`-Oz]
this.nSplitter = nSpiltter; ic(`Ev
(!B1}5"
nkn4VA?"
} .P^&sl*J
yTb#V"eR
JcDcYB
public String getSSiteURL() 1Vy8TV3D
{ \DC0`
return sSiteURL; :@8N${7`$A
} \&Zp/;n
i~0x/wSl_
.Do(iYO.L
public void setSSiteURL(String value) Tz?0E"yx
{ 70BLd(?
sSiteURL = value; 3q*p#l~
} Uop`)
sOUQd-!"
nWz7$O
public String getSFilePath() ;S.o`z1GI
{ kzuI<DW
return sFilePath; zIT)Hs5
} ;*}tbh3;.
(764-iv(
L.tW]43K
public void setSFilePath(String value) fS#I?!*}
{ 6(0ME$
sFilePath = value; j|Hyv{sM
} $4ZjNN@
9 m`VIB
]]^eIjg>a6
public String getSFileName() 6k-
{ 'BOMFp7c
return sFileName; bc}BQ|Q
} 2Mo oqJp
O; #qG/b1
\\UOpl
public void setSFileName(String value) (@&+?A"6`
{ QRKr2:o{
sFileName = value; :qe.*\ c
} ?hh#@61
1@S(v L3a
NwbX]pDT
public int getNSplitter() EwX:^1f
{ bDADFitSo
return nSplitter; JKy06I
} <A`zK
xjK@Q1MJ
+ko-oZ7V
public void setNSplitter(int nCount) #m;|QWW
{ |\3X7)^8D
nSplitter = nCount; E,p4R%:$@1
} PyQ P K,
} }u?DK,R
>,}SP;
&\>.j|
/* RoYwZX~
**Utility.java rMEM$1vPU
*/ 5|_El/G
package NetFox; 3K{G=WE$
6s(.ul
%&}gt+L(M
public class Utility { fZka$ 4
vMv? fE"
f)#rBAkt
public Utility() eB2a1<S&@
{ R.P|gk
q'1 86L87
8ZL9>"%l
} X(M|T]`b:
G{]tB w
//线程睡眠 gPqdl6#c
public static void sleep(int nSecond) U]}f]GK
{ >#[,OU}N
try{ o/4U`U)Q0v
Thread.sleep(nSecond); uG,*m'x']
} |kK_B :K
catch(Exception e) 26B+qXEt
{ 94Q?)0W$
e.printStackTrace (); *w5xC5*
} *wp>a?sG\
} _Y _v&
C2(VYw
//日志 JS2h/Y$
public static void log(String sMsg) w tSX(LNY
{ n=qu?xu
System.err.println(sMsg); |!hN!j*)
} + C'<*
Lm1 -
ESi'3mbeC
public static void log(int sMsg) Gph:'3 *X
{ ?M9?GodbP.
System.err.println(sMsg); JrNqS[c/
} pKNrEq
} *iiyU}x
/5N`Euw
,.]1N:
/* /ei(Q'pc[
**TestMethod.java 6xiCTs0@
*/ N'n\_x
package NetFox; :878q TB
KvY1bMU!
*|Bt!
public class TestMethod { Ju"K"
Lpv,6#m`)
^t}8E2mq
public TestMethod() Gy6PS{yY6t
{ ///xx/weblogic60b2_win.exe &ieb6@RO`Q
try{ " 3tk"#.#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AR3v,eOs
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y134m
SiteFileFetch fileFetch = new SiteFileFetch(bean); yt[*4gF4
fileFetch.start(); Xv2Q8-}w
} ;i-<dAV8B
catch(Exception e){e.printStackTrace ();} V(wANvH
'dJ(x
0HPqoen$
} H$rNT/C
lN~u='Kc
z$Z{ LR
public static void main(String[] args) \'.|7{Xu
{ s6(bTO.
new TestMethod(); `G "&IQ8.
} F2!]T=
} ;!pSYcT,
点击下载更多相关资料