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)); q!;u4J
} )&6ZgRq
for(int i=0;i<nEndPos.length-1;i++) LA]UIM@
{ 6L<Y
nEndPos = nStartPos[i+1]; jWL%*dJrN
} JIc(hRf9>
nEndPos[nEndPos.length-1] = nFileLength; H|)F-aL[
} *Z8qd{.$q
} Uee(1
S:lie*Aux*
eC{St0
//启动子线程 8AVtUU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AXpg_JC
for(int i=0;i<nStartPos.length;i++) .QU]
{ x?7z15\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v?Zo5uVoq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DuQW?9^232
nStartPos,nEndPos,i); {h*)|J
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -{XDQ{z<%
fileSplitterFetch.start(); ZS<`.L6B3
} nV:RL|p2jw
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KwHlpW*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); XvSng"f.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", icK$W2<8mg
nEndPos = " + nFileLength); (nu;o!mo9
// fileSplitterFetch[nPos.length-1].start(); 4iDqd
XEBeoOX/
dI+Y1Vq
//等待子线程结束 _]v@Dq VP
//int count = 0; x,NV{uG$n
//是否结束while循环 8'PK}heBU
boolean breakWhile = false; 2#(dfEAy
mCe"=[
WES$B7y
while(!bStop) 2kcDJ{(
{ S2jn pf}
write_nPos(); Q7#t#XM
Utility.sleep(500); W m&*
breakWhile = true; 0`/CoP<U
Q{|_"sfJ
dv Vz#
for(int i=0;i<nStartPos.length;i++) <v6W l\
{ $[g#P^
if(!fileSplitterFetch.bDownOver) 1'!D
{ F%f)oq`B
breakWhile = false; _lDNYpv
break; m[CyvcF*u
} B.C:06E5
} d#HlO}
if(breakWhile) !k Heslvi
break; pAws{3(Q
2w}l!'ue
2>[xe
//count++; <naxpflom0
//if(count>4) iA<'i8$P
// siteStop(); j&u/T
} sXmP<c
@'A0Lq+#
F/PH=Dk
System.err.println("文件下载结束！"); ]O>AD6P
} u9m ~1\R*
catch(Exception e){e.printStackTrace ();} ce[ Maw
} |xF!3GGms
OZ33w-X<
9#>nFs"H
//获得文件长度 #KNl<V+c}1
public long getFileSize() 0|<9eD\I=
{ vb| d
int nFileLength = -1; BRa9j:_b
try{ ^xgqs $`7
URL url = new URL(siteInfoBean.getSSiteURL()); Vr@tSc&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R$p(5>#\5
httpConnection.setRequestProperty("User-Agent","NetFox"); 3Vbt(K
CZE!@1"<{
on;>iKta9
int responseCode=httpConnection.getResponseCode(); FJ{/EloF
if(responseCode>=400) &2Ef:RZF
{ gA`QV''/:
processErrorCode(responseCode); JZK93R
return -2; //-2 represent access is error 7GTDe'T
} v>HOz\F
CH#K0hi
W~PMR/^i
String sHeader; Yw yMCd
rog1
A2ufET
for(int i=1;;i++) q65]bs4M
{ $Dd-2p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mE=Ur
//Utility.log(in.readLine()); ?6]B6
sHeader=httpConnection.getHeaderFieldKey(i); ~%2yDhdQ
if(sHeader!=null) +MD84YR
{ 'N^*,
if(sHeader.equals("Content-Length")) 7n?yf_je
{ Z- t&AH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XjdHH.) S
break; {\vVzy,t7
} :T|9;2
} V;W{pd-I
else %NfXe[T
break; 3yw$<lm
} +hKs
} `!spi=f
catch(IOException e){e.printStackTrace ();} =av0a!
catch(Exception e){e.printStackTrace ();} ;l1.jQh
8rx|7
as'yYn8
Utility.log(nFileLength); rW090Py
Bd7B\zM
^BM !TQ%!
return nFileLength; 8;L;R~Q
} PxQQfI>
,"KfZf;?
]Y-Y.&b7t
//保存下载信息（文件指针位置） |N^"?bSt
private void write_nPos() Qwt0~9n(
{ ZJenwo
try{ g?xD*3<
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4U_+NC>b
output.writeInt(nStartPos.length); 73]8NVm
for(int i=0;i<nStartPos.length;i++) F,A+O+
{ g$jTP#%b
// output.writeLong(nPos); yXoNfsv
output.writeLong(fileSplitterFetch.nStartPos); FZW`ADq]
output.writeLong(fileSplitterFetch.nEndPos); =36fS/Gb
} K a& 2>F
output.close(); PO8Z2"WI
} Z#B}#*<C
catch(IOException e){e.printStackTrace ();} ; o Y|~
catch(Exception e){e.printStackTrace ();} |d&C<O;f
} I`*5z;Q!%@
S0Io$\ha
kz1#"8Zd!
//读取保存的下载信息（文件指针位置） /a<UKh:A[
private void read_nPos() Kc95yt
{ 7y&6q`y E
try{ nu7 R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [^?i<z{0C
int nCount = input.readInt(); Z'>UR.g
nStartPos = new long[nCount]; ;HH%OfQq
nEndPos = new long[nCount]; G<=I\T'g;
for(int i=0;i<nStartPos.length;i++) Y<u%J#'[
{ /Jc{aw
nStartPos = input.readLong(); 8nu!5 3
nEndPos = input.readLong(); Pc=ei
} 0O,;[l
input.close(); !mTq6H12 !
} LSA6*Q51
catch(IOException e){e.printStackTrace ();} !'~Ldl
catch(Exception e){e.printStackTrace ();} /8Y8-&K0
} FZn1$_Svr
?ueL'4Mm
]hS<"=oj
private void processErrorCode(int nErrorCode) Z$g'h1,zW
{ -3i(N.)<;
System.err.println("Error Code : " + nErrorCode); AWi>(wk<
} c+E\e]{
T7"QwA
qD4s?j-9
//停止文件下载 ~?Vod|>
public void siteStop() n@ SUu7o
{ %3~miP
bStop = true; qR!ZtJ5j
for(int i=0;i<nStartPos.length;i++) [uHU[ sG
fileSplitterFetch.splitterStop(); Z{BK@Q4z
R.*;] R>M
<W!nlh
} @2L^?*n=
} R;pW,]}g,
//负责部分文件的抓取 xjiV9{w
**FileSplitterFetch.java z/`+jIB
*/ l^ay*H
package NetFox; ?8{Os;!je
x'|9A?ez@Z
Jk-WD"J6
import java.io.*; $x`HmL3Sb
import java.net.*; !L{mE&
3e;|KU
/KWdIP#
public class FileSplitterFetch extends Thread { sZCK?
?wPTe^Qtv
#7Q9^rG
String sURL; //File URL D.:`]W|
long nStartPos; //File Snippet Start Position vT0Op e6m
long nEndPos; //File Snippet End Position }=)u_q
int nThreadID; //Thread's ID TK18U*z7J
boolean bDownOver = false; //Downing is over 'g,_lF
boolean bStop = false; //Stop identical gJX"4]Ol#}
FileAccessI fileAccessI = null; //File Access interface __xmn{{L6P
o]4BST(A
.pWRV<25
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b#p0s?*
{ uP%VL}%0
this.sURL = sURL; ed/B.SY
this.nStartPos = nStart; v~Dobk/n
this.nEndPos = nEnd; F?R6zvive
nThreadID = id; ?_d>-NC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8|{ZcW
} 8tR6.09'
J)B3o$
L!l?tM o
public void run() o.NU"$\?
{ &4|]VOf
while(nStartPos < nEndPos && !bStop) lqv}~MC
{ Q2Ey RFT
?OF$J|h
1="]'!2Is
try{ fqbeO9x
URL url = new URL(sURL); VnSO>O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9)]`le
httpConnection.setRequestProperty("User-Agent","NetFox"); eA(\#+)X `
String sProperty = "bytes="+nStartPos+"-"; Ncbe{}<md
httpConnection.setRequestProperty("RANGE",sProperty); O0z-jZ,])
Utility.log(sProperty); h ChO
]}].Aq
@xBb|/I
InputStream input = httpConnection.getInputStream(); 9ThsR&h3
//logResponseHead(httpConnection); QxE%C
ty~Sf-Pri
O4f9n
byte[] b = new byte[1024]; Lf^ 7|
int nRead; Y=<ABtertS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~FYC'd
{ yC5>k;/6#K
nStartPos += fileAccessI.write(b,0,nRead); 6wB !dl
//if(nThreadID == 1) ef{Hj[8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G@D;_$a
} eWm'eO
<:/aiX8
#UymD-yII
Utility.log("Thread " + nThreadID + " is over!"); Z"Hq{?l9
bDownOver = true; :RB7#v={
//nPos = fileAccessI.write (b,0,nRead); *8a[M{-X
} /G7^l>pa
catch(Exception e){e.printStackTrace ();} y@*4*46v
} i: UN
} C$])q`9
(AZneK :*
ld(_+<e
//打印回应的头信息 / zNVJhC
public void logResponseHead(HttpURLConnection con) :/=P6b;
{ 8q9^
for(int i=1;;i++) w/o8R3F
{ 9m>L\&\_e
String header=con.getHeaderFieldKey(i); e[T3,2C
if(header!=null) teDRX13=;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b}7g>
Utility.log(header+" : "+con.getHeaderField(header)); ~P,Z@|c4
else nY1PRX\
break; xP1D 9
} aMydeTCHi
} ZT&[:>upR
"N%W5[C{
j^8Hjg
public void splitterStop() 7SkW!5
{ ,:}VbQ:3I
bStop = true; md{1Jn"
} 78xiT
=u9e5n
U/q"F<?.c
} $?kTS1I(
P!9-!+F"
Ve[Kv07
/* :X9;KoJl-V
**FileAccess.java GPs4:CIgG
*//文件访问(定位，写) Rb b[N#p5
package NetFox; u5qaLHoEP
import java.io.*; su\Lxv
O>X!78]#K
Q"pZPpl&
public class FileAccessI implements Serializable{ -y&>&D
u^ wGVg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0\ j)!b
RandomAccessFile oSavedFile; cru&nH*O^
long nPos; GF<SQHL,
w"Zws[pm]
z9AX8k(B6
public FileAccessI() throws IOException E0r#xmk
{ :]\-GJV5
this("",0); * e,8o2C$
} M#],#o*G
kbz+6LcV
2U+wiE|
public FileAccessI(String sName,long nPos) throws IOException ,5*<C'9
{ R<h:>.M
oSavedFile = new RandomAccessFile(sName,"rw"); "wV7PSbM
this.nPos = nPos; W7V#G(cpU
oSavedFile.seek(nPos); "[L+LPET
} =%FhY^-
_3KfY
IU}g[OCu
public synchronized int write(byte[] b,int nStart,int nLen) ]tK<[8Y
{ gavf$be
int n = -1; V,tYqhQ3
try{ :VRQd}$Pi
oSavedFile.write(b,nStart,nLen); Q;2kbVWY
n = nLen; J0@#xw=+
} ,tFLx#e#
catch(IOException e) GV)DLHiyxX
{ Vc|QW
e.printStackTrace (); Mm"0Ip2"
} +{e2TY
b Oh[(O!
jvE&%|Ngw
return n; ,}OQzK/"mP
} ",E$}= ,Z
P'5Q}7
$kQQdF
} 8`w#)6(V
#)%dG3)e
+N:M;uTS
/* y7 W7270)
**SiteInfoBean.java PsS8b
*/ 3 _DJ
package NetFox; y=y#*yn&
kvt"7;(
5m6I:s`pK
public class SiteInfoBean { s)~H_,
c$%I^f}'
6k\8ulHw
private String sSiteURL; //Site's URL 7LW%:0
private String sFilePath; //Saved File's Path \9.@Tg8`
private String sFileName; //Saved File's Name v.H@Ey2
private int nSplitter; //Count of Splited Downloading File ~{yQsEU
"g;}B"rG
K&vqk/JW1
public SiteInfoBean() V@ph.)z
{//nSplitter的缺省值为5 =G/`r!r*0I
//default value of nSplitter is 5 H 4W4#\M
this("","","",5); n<7R6)j6
} r?n3v[B
*3Ci4\Ew
.sPa${
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ba|76OBRJ
{ $k3l[@;hE
sSiteURL= sURL; -f[95Z3}
sFilePath = sPath; ^5gB?V,
sFileName = sName; gtb,}T=1
this.nSplitter = nSpiltter; mt3j$r{_
7;:Uv=
o>4GtvA*
} Q(YQ$i"S
2Yd;#i)
DKf:0E8
public String getSSiteURL() >_?Waz%
{ (V+iJ_1g{
return sSiteURL; +D+Rf,D
} w=75?3c7F
6~6*(s|]A
6Yx/m
public void setSSiteURL(String value) {f)"F;]V
{ j%s:d(H`
sSiteURL = value; 3LD`Ep
} 6oLq2Z8uP
y{\K:
?qjlWCV|e
public String getSFilePath() !+I!J s"
{ q]o^Y
return sFilePath; |b:91l
} , 8F(R%v
ZzuWN&
z@em1W0?Z
public void setSFilePath(String value) d_}q.%*
{ 2r&T.
sFilePath = value; r$Ck:Q}
} <ekLL{/O'
d>NM4n[h8
R~DZY{u+/$
public String getSFileName() 7vs>PV
{ kFHtZS(
return sFileName; "Dwaq*L
} n$y)F} .-
4!KUPgg
qBIKJ
public void setSFileName(String value) ?KfV>.()
{ j5>3Td.
sFileName = value; v=I 'rx
} 07L1 "
/"<o""<]
$>fMu
public int getNSplitter() ^h@1tFF
{ :|?nz$
return nSplitter; As7Y4w*+
} mN:p=.& <
1tQl^>r16
?N*|S)BN
public void setNSplitter(int nCount) r8E)GBH-|
{ AR-&c 3o
nSplitter = nCount; Xy(o0/7F9
} 7 a}qnk%
} \{ui{8+G
2,X~a;+
ESl</"<J
/* $NtbI:e{
**Utility.java _*O^|QbM
*/ +5+?)8Ls
package NetFox; 4>&%N\$*
^l4=/=RR
.:b|imgiv
public class Utility { -C|1O%.
>f$>Odqe
yJ&`@gB
public Utility() p|z\L}0
{ ^sp+ sr :
M6P`~emX2
@;we4G5
} Sp=6%3fZ]m
[l2ds:
//线程睡眠 gz?]]-H
public static void sleep(int nSecond) 1 f;k)x
{ E$'Zd,|f=
try{ OA_Bz"
Thread.sleep(nSecond); 5:ZM-kZT
} ']hB_4v
catch(Exception e) Wb/q&o
{ Ty21-0F
e.printStackTrace (); H7KcPN(0
} sacaL4[_<
} jz%%r Q(
i0%S6vmaS
//日志 7aJLC!
public static void log(String sMsg) L/,W
{ f"j"ZM{~U
System.err.println(sMsg); :i&ZMH,O
} jcWv&u|
^hhJ6E_W
MW^,l=kqW)
public static void log(int sMsg) ZV`D} CQ
{ %C!u/:.Kv
System.err.println(sMsg); EhkvC>y
} h$Z_r($b
} ix<sorR H
k#I4^
hDp -,ag{
/* JwNG`MGc
**TestMethod.java K>2mm!{
*/ yE(>R(^
package NetFox; a+TlZE>8
q89#Ftkt
ztNm,1pnQ
public class TestMethod { `43`*=
Sxrbhnx
4,!S?:7
public TestMethod() )pS1yYLj
{ ///xx/weblogic60b2_win.exe 4|ryt4B
try{ aD aQ7i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0B^0,d(s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CF`tNA3fxm
SiteFileFetch fileFetch = new SiteFileFetch(bean); Lzzf`jN]
fileFetch.start(); S(^*DV
} ]OE{qXr{
catch(Exception e){e.printStackTrace ();} 0jsU^m<g
9OeY59 :
\>8"r,hG|
} +1Ha,Ok
li4rK<O
Ng?n}$g*
public static void main(String[] args) f-N:
{ 2t3'"8xJ
new TestMethod(); )SMS<J
} %t&5o>1C
} AR i_m
点击下载更多相关资料