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)); ^D]J68)#a
} blWtC/!Aq;
for(int i=0;i<nEndPos.length-1;i++) H|0-Al.{
{ eIEL';N6
nEndPos = nStartPos[i+1]; W':b6}?
} @U4hq7xzV2
nEndPos[nEndPos.length-1] = nFileLength; l[]cUE
} )"?eug}D
} d&+0JI<
?K;l 5$?%
jU kxA7 }}
//启动子线程 Yg?BcY\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tUuARo7#
for(int i=0;i<nStartPos.length;i++) Y]*&\Ex"\
{ %Oo f/q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \4LTViY]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Fg 8lX9L
nStartPos,nEndPos,i); (c&%1bJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IBvn q8\
fileSplitterFetch.start(); S8B?uU
} ZqdoYU'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nbB*d@"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); , O/IY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :5['V#(o
nEndPos = " + nFileLength); Ozhn`9L+1!
// fileSplitterFetch[nPos.length-1].start(); 6" <(M@
xmEom
Y+o\?|q-E
//等待子线程结束 [KFCc_:
//int count = 0; q2r$j\L%
//是否结束while循环 $.t>* Bq
boolean breakWhile = false; mBJr*_p
D)pTE?@W'
).IyjHY
while(!bStop) vBJxhK-
{ 8MI8~
write_nPos(); uO-|?{29
Utility.sleep(500); c_CVZR?
breakWhile = true; g~b$WV%
Bu&9J(J1
_si5z
for(int i=0;i<nStartPos.length;i++) @tPr\F
{ K3<A<&W_-
if(!fileSplitterFetch.bDownOver) ;BqCjS%`N
{ n((A:b
breakWhile = false; zfE8=d8U
break; >MKj~Ud
} k0O5c[j
} %LzARTX
if(breakWhile) _yUYEq<`
break; S6_:\Q
*Ti"8^`6
]j>`BK>FE
//count++; XXhN;-p
//if(count>4) W8$0y2
// siteStop(); 122s7A
} JBLUX,
<&3aP}
~".@;Q
System.err.println("文件下载结束！"); Zhv%mUj~
} VH~YwO!x
catch(Exception e){e.printStackTrace ();} :F@Uq<~(
} 2IE\O8b
YvcV801Go
x{8h3.ZQ,
//获得文件长度 b>8TH-1t~
public long getFileSize() A6 .wXv,
{ JB].ht
int nFileLength = -1; @{q<"hT
try{ \o/eF&
URL url = new URL(siteInfoBean.getSSiteURL()); M2w'cdHk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I#M>b:"te
httpConnection.setRequestProperty("User-Agent","NetFox"); Dw7Xy}I/
\>pm (gF
'2i !RT-
int responseCode=httpConnection.getResponseCode(); ^9Cu?!xu0
if(responseCode>=400) q^sZP\i,*;
{ ,c^nW
processErrorCode(responseCode); "OK[uug
return -2; //-2 represent access is error 9M3"'^ {$
} NN=^4Xpc:
z'$1$~I
G`kz 0Vk
String sHeader; U|Gy9"
__Ksn^I
Hnk&2bY
for(int i=1;;i++) aA52Li
{ P_NF;v5v
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~gW^9nWYU
//Utility.log(in.readLine()); d)bsyZ;U
sHeader=httpConnection.getHeaderFieldKey(i); :>;F4gGVG
if(sHeader!=null) r~h#
{ LtX53c
if(sHeader.equals("Content-Length")) R'zi#FeP
{ v\4<6Z:4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *9$SFe|&n:
break; jq*`| m;Q
} j}",+Hv
} pvsa?z;rP
else 0"%dPKi
break; ;aWk-
} ;h+~xxu=X
} [RN]?,
catch(IOException e){e.printStackTrace ();} :o{,F7(P
catch(Exception e){e.printStackTrace ();} Gj-nTN
\>Rfa+
|k90aQO
Utility.log(nFileLength); -5 PVWL\
rvy%8%e?
^7gKs2M
return nFileLength; 0V>HoH
} 5!fYTo|G>
r>FwJm!
]#^v754X^T
//保存下载信息（文件指针位置） ]S[/a
private void write_nPos() E5)0YYjHZ
{ 9l&q}
try{ 6V]m0{:E
output = new DataOutputStream(new FileOutputStream(tmpFile)); :,aY|2si
output.writeInt(nStartPos.length); zA>X+JH>iw
for(int i=0;i<nStartPos.length;i++) !|xB>d q?
{ QJ4$) Fr(
// output.writeLong(nPos); `3i>e<m~
output.writeLong(fileSplitterFetch.nStartPos); <MkvlLu((o
output.writeLong(fileSplitterFetch.nEndPos); ~Ay)kv;
} @}g3\xLiK
output.close(); }URdoTOvb
} :R=6Ku>
catch(IOException e){e.printStackTrace ();} -wiQd@X
catch(Exception e){e.printStackTrace ();} 4xmJQ>/
} J|f29B-c
c_*w<vJ-'
i$<['DY
//读取保存的下载信息（文件指针位置） 5X)M)"rq;V
private void read_nPos() *$-X&.h[
{ jb&MC2
try{ y< *-&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v{ >3)$1
int nCount = input.readInt(); JOY&YA$U
nStartPos = new long[nCount]; XyE$0i~t
nEndPos = new long[nCount]; ^ZQMRNP{r
for(int i=0;i<nStartPos.length;i++) }rfikm
{ "Mj#P9
nStartPos = input.readLong(); m =b7 r
nEndPos = input.readLong(); i83~&Q=
} 8R3{YJ6@T
input.close(); xt?-X%oY8
} \Dq'~ d
catch(IOException e){e.printStackTrace ();} rN}8~j
catch(Exception e){e.printStackTrace ();} bc'IoD/
} 2wY|E<E
EwN{|34C
^_Hf}8H7]
private void processErrorCode(int nErrorCode) f1ANziC;i
{ GT<oYrjU
System.err.println("Error Code : " + nErrorCode); d'ZNp2L
} }`<&l
Ph[MXb:*
D/."0 #q
//停止文件下载 /Rq\Mgb
public void siteStop() "x=\mA#`
{ '?veMX
bStop = true; w/nohZF6H
for(int i=0;i<nStartPos.length;i++) ~h3G}EH
fileSplitterFetch.splitterStop(); ?<!qF:r:
Uw.')ZY=
Z5 IWoY
} OA3J(4!"W
} MZ,1mR
//负责部分文件的抓取 <N=k&\
**FileSplitterFetch.java YJ6~P
*/ W34xrm
package NetFox; BjvQ6M{Y"+
2 3PRb<q
-|m3=#
import java.io.*; JK =A=
import java.net.*; #!R>`l(S
}b(hD|e
Mc@9ivwL#
public class FileSplitterFetch extends Thread { JfN5#+_i
$3HqVqF^R
*XhlIQ
String sURL; //File URL JKM(fX+
long nStartPos; //File Snippet Start Position 0AQ4:KV(Y
long nEndPos; //File Snippet End Position I </P_:4G
int nThreadID; //Thread's ID f $Agcy
boolean bDownOver = false; //Downing is over "i;.>
boolean bStop = false; //Stop identical sq_>^z3T
FileAccessI fileAccessI = null; //File Access interface c]|vg=W
1PwtzH.w
7<^+)DsS?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R xITMt
{ \yJ 4+vo2Q
this.sURL = sURL; +QFKaS<sn
this.nStartPos = nStart; !+PrgIp>
this.nEndPos = nEnd; dRron_'
nThreadID = id; Jj \nye+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hUlRtt
} _ Lh0
_C/|<Ot:
L K#A
public void run() o7!A(Eu
{ _k2R^/9Ct%
while(nStartPos < nEndPos && !bStop) QAV6{QShj
{ dP8qP_77A~
kT@ITA22
I+& T}R
try{ A`3KE9ED
URL url = new URL(sURL); '0+I'_(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ydzsJ+dx
httpConnection.setRequestProperty("User-Agent","NetFox"); d*^JO4'
String sProperty = "bytes="+nStartPos+"-"; VxN#\Di&
httpConnection.setRequestProperty("RANGE",sProperty); as:l1S
Utility.log(sProperty); 5?>4I"ne
KY
l[T-Ak
InputStream input = httpConnection.getInputStream(); )4ek!G]Rb
//logResponseHead(httpConnection); F+H]{ss>
v8f3B<kj
@GKDSS4jv
byte[] b = new byte[1024]; SiaNL:
int nRead; Z?o0Q\}1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) aze#Cn,P}
{ ElW\;C:K*
nStartPos += fileAccessI.write(b,0,nRead); MeBTc&S<
//if(nThreadID == 1) Z2]0brV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mKe6rEUs|
} S5hc@^|0Z
arm_SyL0
XS&Pc
Utility.log("Thread " + nThreadID + " is over!"); *U1*/Q.
bDownOver = true; ?_gvI
//nPos = fileAccessI.write (b,0,nRead); nnPT08$
} \XB,)XDB
catch(Exception e){e.printStackTrace ();} swj\X,{
} m=6?%' H}
} v)du]
9Ad%~qciY
1!1JT;gG^9
//打印回应的头信息 4~Cf_`X}]
public void logResponseHead(HttpURLConnection con) Jq` Dvz
{ Gky*EY
for(int i=1;;i++) m-O*t$6
{ ,h^6y
String header=con.getHeaderFieldKey(i); QIkFX.^
if(header!=null) gV@xu)l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aftt^h
Utility.log(header+" : "+con.getHeaderField(header)); @sn:%/x_
else "Y+VNS
break; `?$-T5Rr
} yT/rH- j;5
} 7-B|B{]
rB+ (
epnZGz,A
public void splitterStop() mHMsK}=~
{ DIGw4g4Kt
bStop = true; 6Mc&=}bV
} k5\V:P=#
t[!,puZc#
M#^q <K %
} D/=05E%[81
Lmjd,t
Gk5'|s
/* ]#M"|iTR
**FileAccess.java 2*D2jw
*//文件访问(定位，写) F4\:9ws
package NetFox; aZ~e;}w.Zq
import java.io.*; rwDLBpk
N#M>2b<A/T
: _Y^o
public class FileAccessI implements Serializable{ \xS X'/G
h:pgN,W}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 PNAvT$0LaZ
RandomAccessFile oSavedFile; rmw}Ui"
long nPos; 2Di~}*9&
ByjfPb#
]B(}^N>WH
public FileAccessI() throws IOException l#cVQ_^"
{ Kc]cJ`P4.
this("",0); mdL T7
} ? /!Fv/
|E K6txRb
RbUir185Y
public FileAccessI(String sName,long nPos) throws IOException +DSbr5"VlB
{ )q'dX+4=eL
oSavedFile = new RandomAccessFile(sName,"rw"); w31O~Ve
this.nPos = nPos; ^kNVQJiZyG
oSavedFile.seek(nPos); =Jl\^u%H(x
} [UkcG9
?5">50
\_.'/<aQ
public synchronized int write(byte[] b,int nStart,int nLen) mL1ZSX o!
{ 1R-0b{w[
int n = -1; 1W*Qc_5 v1
try{ ?:vg`m!*
oSavedFile.write(b,nStart,nLen); wOL%otEf
n = nLen; 53uptQ{
} 60~*$`
catch(IOException e) MDa[bQNM
{ FsUH/Y y
e.printStackTrace (); '*Y mYU
} Nkb%4ofKqu
9hK8dJw
* g+v*q X
return n; o7we'1(O
} im<!JMI
C|H`.|Q
a.u{b&+9
} ?z)2\D
\Yp"D7:Qi
t#M[w|5?
/* ';.TQ_I7Y
**SiteInfoBean.java o$bQ-_B`
*/ Y]R=z*i%
package NetFox; EO'+r[Y
9J%O$sF
Q +hOW-
public class SiteInfoBean { br0\O
+ ,]&&
xz@*V>QT
private String sSiteURL; //Site's URL ly!3~W
private String sFilePath; //Saved File's Path *W2] Kxx*
private String sFileName; //Saved File's Name Pi[]k]XA\
private int nSplitter; //Count of Splited Downloading File q:vN3#=^qf
hTAc}'^$
$igMk'%Nmb
public SiteInfoBean() ZK{1z|
{//nSplitter的缺省值为5 w2 (}pz:
//default value of nSplitter is 5 unYPvrd
this("","","",5); oVuIHb0w
} 5Mxl({oI]
cJT_Qfxx
S%]4['Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4myikeUR_
{ 5Q}HLjG8Z
sSiteURL= sURL; !bK;/)
sFilePath = sPath; #/(L.5d[
sFileName = sName; :'t"kS
this.nSplitter = nSpiltter; \py&v5J)s!
N<(rP1)`v
9%k4Ic%P
} ! ,]Fx
Qmd2C&Xw
+CEt:KQ
public String getSSiteURL() #I ,c'Vj
{ %D7^.
return sSiteURL; /ORK9g
} KPK`C0mg@k
|<]wM(GxE
%RIu'JXi
public void setSSiteURL(String value) ctb , w
{ pdQaVe7tRo
sSiteURL = value; M(^IRI-
} -uAGG?ZER
dg N#"
cw BiT
public String getSFilePath() _Axw$oYS
{ qqYQ/4Ajw
return sFilePath; dZ,7q_r,~
} tr 8Q{
N:^4OnVR
C`oB [
public void setSFilePath(String value) }D~m%%,
{ &@&^k$du8q
sFilePath = value; ='/#G0W
} Y% [H:
&6Wim<*
jN+2+P%OL
public String getSFileName() mh_GYzd
{ \bSakh71
return sFileName; H/#WpRg
} fK4O N'[R:
)]}68}9
Df$Yn
public void setSFileName(String value) z_&T>ME
{ x6yO2Yo
sFileName = value; ,l)AYu!q4F
} k"`^vV[{F
Z!?T&:
j~ qm5}
public int getNSplitter() G#^6H]`[J:
{ G|$n,X1O(
return nSplitter; dfeN_0`-
} B<!wh
1N8YD .3
BGT`) WP
public void setNSplitter(int nCount) xiQd[[(sM
{ 1$c[G}h
nSplitter = nCount; kb*b|pWlO
} =?B[oq
} vinn|_s%
na/,1iI<
7 (i\?
/* n22OPvp
**Utility.java jAFJ?L(
*/ 7mS_Cz+cB
package NetFox; 0vz!)
H%Sx*|
Gc!&I+kd
public class Utility { '^t(=02J
2f0_Xw_V_
|i'w"Tz4
public Utility() Uv3Fe%>
{ ~!dO2\X+
(7PVfS>;
E+aE5wmr
} Luh*+l-nO
y=WCR*N
//线程睡眠 p["20?^
public static void sleep(int nSecond) B\7 80p<
{ t4,(W`
try{ FE?^}VH
Thread.sleep(nSecond); ^t)alNGos
} O$&4{h`
catch(Exception e) k{C|{m
{ )0@&pEObm
e.printStackTrace (); ^$\#aTyFK
} {[FJkP2l
} 8F`799[p
R 9Yk9v
//日志 yCye3z.
public static void log(String sMsg) ZltY_5l
{ 2W`<P2IA
System.err.println(sMsg); {&Sr<d5
} 8J#TP7;
HFf9^
LfS]m>>e
public static void log(int sMsg) )pt#Pu
{ NY~y:*:Q
System.err.println(sMsg); ehYGw2
} []eZO_o6j
} bMF`KRP2
9RN! <`H
qgLj^{
/* ]a=Bc~g91
**TestMethod.java !xZ`()D#
*/ Ja6PX P]'
package NetFox; qeZ*!H6-
u'EzYJ7
E@$HO_;&
public class TestMethod { c`G~.paY|
V4 Wn
|zSoA=7?
public TestMethod() %L;'C v
{ ///xx/weblogic60b2_win.exe +LAjh)m
try{ qw%wyj7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }>u<,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5U&?P
SiteFileFetch fileFetch = new SiteFileFetch(bean); &8wluOs/5
fileFetch.start(); 3sq(FsT
} *6%r2l'kZ
catch(Exception e){e.printStackTrace ();} '@+a]kCMev
{VrjDj+Xy
<swYo<?J#
} vErlh:~e
#EdsB
['n;e:*
public static void main(String[] args) $3MYr5
{ HGRH9W
new TestMethod(); 6*H F`@(
} 'xY@I`x
} s\dF7/b
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