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)); '*K%\]
} w!Ii
for(int i=0;i<nEndPos.length-1;i++) oe=W}y_k
{ G~f|Sx
nEndPos = nStartPos[i+1]; VE^IA\J x
} 6MQyr2c
nEndPos[nEndPos.length-1] = nFileLength; t2FA|UF
} 2=n,{rkmj%
} K6nNrd}p:
=BeJ.8$@VC
Fw%S%*B8g
//启动子线程 'D^@e0.3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0BP=SCi
for(int i=0;i<nStartPos.length;i++) N1dM,H
{ [4mIww%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '.XR,\g>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A/~^4DR
nStartPos,nEndPos,i); "iuNYM5P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z+j3j2
fileSplitterFetch.start(); ^B(:Hv}G(:
} zoau5t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =qww|B92
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 88zK)k{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r@G34QC+
nEndPos = " + nFileLength); %p^`,b}
// fileSplitterFetch[nPos.length-1].start(); H `_{n<
gV-A+;u
xsx0ZovhY
//等待子线程结束 h?vt6t9
//int count = 0; E~`<n]{G-C
//是否结束while循环 #mRT>]di`D
boolean breakWhile = false; ]fU0;jzX
Yo,n#<37
.QDeS|l
while(!bStop) awOH50R
{ f}Uf*Bp
write_nPos(); dK7BjZTJo
Utility.sleep(500); nOU.=N v`
breakWhile = true; 1*OZu.NdK
;sY n=r
W9jxw4)
for(int i=0;i<nStartPos.length;i++) et@<MU@`
{ e^-CxHwA-
if(!fileSplitterFetch.bDownOver) LbnW(wr6:(
{ p9~$}!ua
breakWhile = false; BB? 4>#D
break; ]U.*KkQ
} *NoixV1>
} P u,JR
if(breakWhile) b4>1UZGW-
break; qyR}|<F8*
d{(NeTs
t:tIzFNv
//count++; 2:;;
//if(count>4) fD2)/5j1
// siteStop(); T0%l$#6v
} tIo b
|) CfO4
kB_T9$0e#
System.err.println("文件下载结束！"); Dn+hI_"#_
} :[ll$5E.
catch(Exception e){e.printStackTrace ();} 1F{,Zr
} =8Gpov1!V~
>4nQ&b.u
B<&g
//获得文件长度 nc.:Wm6Mj
public long getFileSize() p4z thdN[
{ 75H;6(7
int nFileLength = -1; SX[
try{ Xt$Y&Ho
URL url = new URL(siteInfoBean.getSSiteURL()); @$5=4HA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +RyV"&v
httpConnection.setRequestProperty("User-Agent","NetFox"); !PJp()
8T3Nz8Q7
'oF('uR
int responseCode=httpConnection.getResponseCode(); j-7aJj%
if(responseCode>=400) h.5KzC S
{ W@Rb"5Gy+
processErrorCode(responseCode); pSodTG$E
return -2; //-2 represent access is error \qtdbi|Y
} tiF-lq
Sn[/'V^$a
aA'of>'ib|
String sHeader; T (? CDc+
Pdk#"H-j
KxQMPtHstz
for(int i=1;;i++) &A~hM[-
{ c uHF^l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Mt&n|']`8
//Utility.log(in.readLine()); <yw56{w,
sHeader=httpConnection.getHeaderFieldKey(i); j5rMY=|F
if(sHeader!=null) aq- |
{ 5jHr?C
if(sHeader.equals("Content-Length")) |cL,$G
{ j eyGIY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I6PReVIb
break; j8;Uny9
} xMFEeSzl>S
} yacN=]SW5
else R]4 h)"
break; #?'@?0<6
} D+{&zo
} +-qa7
catch(IOException e){e.printStackTrace ();} |mT1\O2a
catch(Exception e){e.printStackTrace ();} ym'!f|9AA
PCnu?e3F
|v_ttJ;+Y
Utility.log(nFileLength); r`Dm;@JU
vK$wc~
XHh*6Yt_ (
return nFileLength; x|)pZa
} 5-UrHbpCZ#
'3xK1Am
`@{(ijg.
//保存下载信息（文件指针位置） 9(lcQuE9
private void write_nPos() V,]Fh5f
{ 4<Kxo\\S
try{ 0rxGb} b*
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q+s2S>U{v
output.writeInt(nStartPos.length); u-*z#e_L0
for(int i=0;i<nStartPos.length;i++) ^0?ww&X
{ HQMug
// output.writeLong(nPos); dtig_s,)D
output.writeLong(fileSplitterFetch.nStartPos); 0S$TLbx
output.writeLong(fileSplitterFetch.nEndPos); hx ^l
} wV\G$|Y
output.close(); #44}Snz
} j{6O:d6([$
catch(IOException e){e.printStackTrace ();} $GYy[8{:V
catch(Exception e){e.printStackTrace ();} &a)d,4e<M
} 8Yo;oHk7
S3&n?\CO:
@U9`V&])F[
//读取保存的下载信息（文件指针位置） )nrYxxN
private void read_nPos() Y7;=\/SV
{ 35L\
try{ I= a?z<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JF=T_SH^U
int nCount = input.readInt(); N?O^"
nStartPos = new long[nCount]; 4gZ)9ya
nEndPos = new long[nCount]; \i\>$'f*z
for(int i=0;i<nStartPos.length;i++) ;te( {u+
{ 4/OmgBo'
nStartPos = input.readLong(); NMUF)ksjN
nEndPos = input.readLong(); M*D@zb0ia
} @FF80U4'
input.close(); r_kaS als
} Q\N >W+d
catch(IOException e){e.printStackTrace ();} ]dgi]R|`
catch(Exception e){e.printStackTrace ();} E<7$!P=z`
} Yv0y8Vz@
!Y&]Y G
Ao#bREm
private void processErrorCode(int nErrorCode) 2*a9mi
{ HE>V\+ AL
System.err.println("Error Code : " + nErrorCode); NE4]i
} tH#t8Tq5x
ta^$&$l
uc}F|O
//停止文件下载 9$D}j"
public void siteStop() <p-@XzyE
{ y=Z[_L!xr
bStop = true; Q<KF<K'0hg
for(int i=0;i<nStartPos.length;i++) mq(-L
fileSplitterFetch.splitterStop(); gtT&97tT<
mA"[x_
uGHM ]"!)
} {?"X\5n0
} Z?V vFEt%
//负责部分文件的抓取 +ej5C:El_}
**FileSplitterFetch.java fxmY,{{
*/ IZ87Px>zL
package NetFox; a*iKpr-:
{fjBa,o #
\v$zU
import java.io.*; ,_s.amL3O{
import java.net.*; sB$"mJ
^bfU>02Q6p
%oWG"u
public class FileSplitterFetch extends Thread { ,~DKU*A_~
]7oo`KcQ|
Jd',v
String sURL; //File URL 5NhAb$q2Y
long nStartPos; //File Snippet Start Position |o*qZ}6
long nEndPos; //File Snippet End Position ]&9=f#k%
int nThreadID; //Thread's ID a .?AniB0
boolean bDownOver = false; //Downing is over AEDBr<
boolean bStop = false; //Stop identical W\mgM2p
FileAccessI fileAccessI = null; //File Access interface eW8{],B
:Nwv&+
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +$#XV@@~
{ 7G*rxn"d
this.sURL = sURL; WFhppi
this.nStartPos = nStart; hwQ|'^(@O
this.nEndPos = nEnd; ,4 q^(
nThreadID = id; />pAZa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {v|ib112;
} 2v;&`04V<
m,J IId%O
e@S$[,8
public void run() <#199`R
{ +$xw0)|
while(nStartPos < nEndPos && !bStop) ;uv$>Fauk
{ N}<!k#d E
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ld):Am}/o
try{ uEG4^
URL url = new URL(sURL); Om>?"=yDE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '.8eLN
httpConnection.setRequestProperty("User-Agent","NetFox"); m-+>h:1b|9
String sProperty = "bytes="+nStartPos+"-"; a/H5Y,b>
httpConnection.setRequestProperty("RANGE",sProperty); M?Q\ Hw
Utility.log(sProperty); x]?V*Jz
!0UfX{.
8 nqF i
InputStream input = httpConnection.getInputStream(); "u&7Y:)^wr
//logResponseHead(httpConnection); /u`Opv&I
mG@[~w+
YC<FKWc
byte[] b = new byte[1024]; `ZO5-E
int nRead; 2PUB@B' +
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2 e#"JZ=
{ Z#[%JUYp'
nStartPos += fileAccessI.write(b,0,nRead); i_+e&Bjd4j
//if(nThreadID == 1) `[XH=-p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ov4 [gHy&
} 0(9gTxdB
Raetz>rL
S4_ZG>\VT
Utility.log("Thread " + nThreadID + " is over!"); wV{j CQ
bDownOver = true; nD)SR
//nPos = fileAccessI.write (b,0,nRead); WE_'u+!B
} 8wZ $Hq
catch(Exception e){e.printStackTrace ();} B#.xs>{N
} YcR: _ac
} ~k?t
_ Qek|>
N1'Yo:_A
//打印回应的头信息 \IzZJGi
public void logResponseHead(HttpURLConnection con) l&"bm C:xr
{ a9_2b}t
for(int i=1;;i++) NNTrH\SU#
{ PJe\PGh
String header=con.getHeaderFieldKey(i); QJ>=a./
if(header!=null) &hi][Pt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HM"(cB(n`
Utility.log(header+" : "+con.getHeaderField(header)); i=M[$
else ?duw0SZ
break; Vhb~kI!x
} @y0kX<M
} gu'+kw
T2mZkK?rA
4"{g{8
public void splitterStop() (5[#?_~
{ YY'[PXP$Y
bStop = true; S_VzmCi
} 6O 2sa-{d
!}1l8Y
?6I`$ &OA
} Aqg$q* Y
ilQ\+xR{b
,p\*cHB9
/* 7Bf4ojKt
**FileAccess.java cRf;7G
*//文件访问(定位，写) ZC^?ng
package NetFox; y4!fu<[i
import java.io.*; dPgA~~
x0TE+rf5
.Dr7YquW
public class FileAccessI implements Serializable{ Tm~jYgJ
l|9'l[}&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R9+f^o`W
RandomAccessFile oSavedFile; }ASBP:c"t
long nPos; W$Aypy
'XSHl?+q
*\Hut'7 d
public FileAccessI() throws IOException )*o) iN 7l
{ x}reeqn
this("",0); L;KLmxy#
} Ww{-(Ktx
x_H"<-By
lw4#C`bx
public FileAccessI(String sName,long nPos) throws IOException lPlJL`e
{ 2b:I.
oSavedFile = new RandomAccessFile(sName,"rw"); )IE)a[wo
this.nPos = nPos; Io_7
oSavedFile.seek(nPos); m :]F&s
} D[Ld=e8t
YeF'r.Y
gti=GmL(L
public synchronized int write(byte[] b,int nStart,int nLen) 3v<9 Z9O
{ "xD5>(|^+Q
int n = -1; u)ZZ/|
try{ "n<u(m8E
oSavedFile.write(b,nStart,nLen); c;R.rV<
n = nLen; B#4 J![BX
} [{_K[5i
catch(IOException e) q0\$wI
{ ;Y(~'KF
e.printStackTrace (); +T7FG_
} HYg7B
]m^ECA$
lHPhZ(Z
return n; /3~}=b
} /p@0Q[E
?T_hK
#Cz:l|\ i
} 8L(KdDY
R~BW=Dz,e
C6b(\#g(
/* c1_?Z
**SiteInfoBean.java PFeK;`[
*/ rB5+~ K@
package NetFox; N" oJ3-~
'MIM_m)H
]5J*UZ}
public class SiteInfoBean { v#+tu,)V;
22m'+3I~Y
v_@&#!u`
private String sSiteURL; //Site's URL p&;,$KDA
private String sFilePath; //Saved File's Path z3-AYQ.H
private String sFileName; //Saved File's Name MT@Uu
private int nSplitter; //Count of Splited Downloading File YyR~pT#ffT
&Lgi
\t@|-`
public SiteInfoBean() V?cUQghHg
{//nSplitter的缺省值为5 6@ )bZ|
//default value of nSplitter is 5 rk(0w|zR+
this("","","",5); "'"dcA
} ]qc2jut"
LHP?!rO0
'GcZxF0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5bKn6O)K
{ \<A@Nf"
sSiteURL= sURL; !b+Kasss9
sFilePath = sPath; c^8y/wfok
sFileName = sName; 1e^-_Bo6'o
this.nSplitter = nSpiltter; o,RLaS,BK'
3^zOG2
th*E"@
} bx<7@
?5 d3k%
#VEHyz6P
public String getSSiteURL() "GofQ5,|
{ `p%&c%*A
return sSiteURL; *l^%7Wrk
} z7J2O
f/qG:yTV`
s0"1W"7vh
public void setSSiteURL(String value) fhmqO0
{ DP9hvu/85
sSiteURL = value; DFt1{qS8@u
} lH^[b[
L[*Xrp;/&
8+1tys
public String getSFilePath() 'DQKpk'
{ 5!G}*u.
return sFilePath; pemb2HQ'4j
} LdAfY0
BS;_l"?
a ^b_&}y
public void setSFilePath(String value) jxr~cp?4
{ amIG9:-1'
sFilePath = value; :- ydsR/
} ?t+Kp9@aZ
MDS;qZx=
>T4.mB7+>
public String getSFileName() u%S&EuX
{ A|8(3PiP
return sFileName; </|IgN$w`
} W9T,1h5x
T'l >$6
.3&zP
public void setSFileName(String value) 0t1WvW
{ ,.uPlnB_
sFileName = value; wEo/H
} C-$S]6
Qd 1Q~PBla
tm(.a?p
public int getNSplitter() |jniI(
{ 8|`4D 'Ln
return nSplitter; -1~bWRYq
} m6)8L?B
eqQAst#~
[MYd15
public void setNSplitter(int nCount) Zycu3%JI
{ VAF+\Cea=
nSplitter = nCount; Y6/'gg'&5
} jx&pRjP
} U&|=dH]-
";cWK29\f
jAmAT/1
/* ]n0kO&
**Utility.java AS[cz! >
*/ 6e$(-ai
package NetFox; 2Tt@2h_L
impzqQlZ,
$6T*\(;T@A
public class Utility { &+=A;Y)
|<P]yn
T%Vii*?M
public Utility() u<./ddC
{ Iw8;",e2
1"009/|
k`6T% [D]
} [XjJsk,
P}y}IR{6
//线程睡眠 Z16G
public static void sleep(int nSecond) _) 2fXG!
{ c$Js<[1
try{ J (Yfup
Thread.sleep(nSecond); EX7cjQsml
} 0n|op:]BHM
catch(Exception e) T+zZOI
{ MRiQaUg2
e.printStackTrace (); 7\'vSHIL
} ?h"+q8&
} bWo-( qxq
V6?ku6k
//日志 f@Rn&&-
public static void log(String sMsg) IL?3>$,
{ \zw0*;&U
System.err.println(sMsg); *r$Yv&c,
} aR ao\Wp|
! R?r)G5E
_ro^<V$%
public static void log(int sMsg) ;(fDR8
{ UP}Ys*
System.err.println(sMsg); lwaxj7
} aErms-~
} A9ia[2[
iXK.QktHw
tbF>"?FY/
/* qP6]}Aj]
**TestMethod.java *x2+sgSf_0
*/ {$)zC*l
package NetFox; t6BggO"_u
j<>E Fd
*P_(hG&c
public class TestMethod { O7%<(
H%> E6rVB
at]=SA
public TestMethod() l7]:b8
{ ///xx/weblogic60b2_win.exe }&Un8Rg"h
try{ eTemRNz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9&fS<Hk
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j}3Avu%
SiteFileFetch fileFetch = new SiteFileFetch(bean); #'fh'$5"
fileFetch.start(); J^8(h R
} Q;W[$yvW
catch(Exception e){e.printStackTrace ();} b}< T<
ma[%,u`
QE*O~Yj
} A(G%9'T
=B<>H$
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public static void main(String[] args) B/.+&AJw
{ 8+K=3=05#U
new TestMethod(); S7]\tw_L)
} B,@geJ
} /|V!2dQs"
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