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)); 0]dL;~0y.
} e ;4y5i
for(int i=0;i<nEndPos.length-1;i++) oGzZ.K3 A
{ 9zj^\-FA_l
nEndPos = nStartPos[i+1]; z0;+.E!
} w[>/(R7im
nEndPos[nEndPos.length-1] = nFileLength; u S$:J:Drx
} r^uo7?gZ^
} `+~@VZ3m
WcyN,5
c}nXMA^^
//启动子线程 Ns6Vf5T.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .Dw^'p>
for(int i=0;i<nStartPos.length;i++) <y+8\m
{ *@'\4OO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &j@i>(7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), } k[gR I]
nStartPos,nEndPos,i); * \@u,[,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kan?2x
fileSplitterFetch.start(); |w(@a:2kw
} tUXq!r<'dT
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @u./VK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +DwyMzeE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;c5Q"
nEndPos = " + nFileLength); Z5/g\G[
// fileSplitterFetch[nPos.length-1].start(); :tu_@3bg-
p]*BeiT#n%
gB!K{ Io'
//等待子线程结束 ~ #Gu:
//int count = 0; h' OLj#H
//是否结束while循环 )-FQ_K%
boolean breakWhile = false; X!0s__IOc
vb{+yEa
M2ig iR
while(!bStop) ,c:Fa)-
{ W`fE@*k0
write_nPos(); CqVh9M.ah
Utility.sleep(500); RHo|&.B;+
breakWhile = true; &Y2mLPB
iw|6w,-)C
<!h&h
for(int i=0;i<nStartPos.length;i++) ]9?_m@Ihx
{ "M*Pt
if(!fileSplitterFetch.bDownOver) ZFy>Z:&S,
{ `F:PWG`
breakWhile = false; p1 tfN$-
break; /#?lG`'1
} v>TI.;{y
} euHX7
if(breakWhile) ;8UHnhk_O
break; Do}mCv
3\6UH
c?L_n=B
//count++; /ey[cm2#[s
//if(count>4) apk06"/
// siteStop(); Fkas*79
} {9KG06%+
2 @g'3M
yKEE @@}\
System.err.println("文件下载结束！"); jcF/5u5e
} *B(na+
catch(Exception e){e.printStackTrace ();} @p jah(i`
} X%!#Ic]Q
IMzhEm
5Bw
//获得文件长度 8cy#[{u`;
public long getFileSize() 95giqQ(N
{ -\@&^e
int nFileLength = -1; t#mW`rGE_
try{ hqVx%4s*J
URL url = new URL(siteInfoBean.getSSiteURL()); :0pxacD"!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y3jb'S4(
httpConnection.setRequestProperty("User-Agent","NetFox"); DUiqt09`~
fL4F ~@`9l
=8 d`qS"
int responseCode=httpConnection.getResponseCode(); ):C4"2l3
if(responseCode>=400) {{M?+]p,^
{ +0;n t
processErrorCode(responseCode); F(/^??<5
return -2; //-2 represent access is error =rS z>l
} -nG3(n&wB
O&]Y.Z9,A
1tG,V%iCp
String sHeader; <#ujm fD
bh:;ovH
0q"&AxNsP
for(int i=1;;i++) C,-q2ry
{ ]J)WcM:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `':$PUz,g
//Utility.log(in.readLine()); s,ZJ?[/
sHeader=httpConnection.getHeaderFieldKey(i); eFvw9B+
if(sHeader!=null) 2a2C z'G
{ LjjE(Yrv{
if(sHeader.equals("Content-Length")) }Tn]cL{]C
{ )` S,vF~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GOHRBV
break; JI5?, )-St
} ^lB'7#7
} %"@KuqV
else $xmltvaF
break; @jg*L2L6
} /AWV@'
} :*TfGV
catch(IOException e){e.printStackTrace ();} h,<%cvU=
catch(Exception e){e.printStackTrace ();} iNf+ -C3
J=W"FEXTL7
Mi.xay%
Utility.log(nFileLength); NvXds;EC
VN|P(S6
"y/GK1C
return nFileLength; yWu80C8q
} ,6,#Lc
6Km@A M]
g+p?J.+
//保存下载信息（文件指针位置） dkJ+*L5
private void write_nPos() )El#Ks5u
{ #sy)-xM
try{ E>xdJ
output = new DataOutputStream(new FileOutputStream(tmpFile)); @rkNx@[~
output.writeInt(nStartPos.length); [2.uwn]i
for(int i=0;i<nStartPos.length;i++) WcAX/<Y>
{ -uenCWF\#
// output.writeLong(nPos); 21M@z(q*
output.writeLong(fileSplitterFetch.nStartPos); /og2+!
output.writeLong(fileSplitterFetch.nEndPos); l,HMm|oU
} Ra[{K@
output.close(); sCSrwsbhv
} U,Nf&g
catch(IOException e){e.printStackTrace ();} TIlcdpwXf
catch(Exception e){e.printStackTrace ();} lM"@vNgK
} !HM{imT
#/!a=0
;OTD1=
//读取保存的下载信息（文件指针位置） Xm*gH, '
private void read_nPos() =:mD)oX*
{ &%L1n?>Q}
try{ ^rjICF e
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \kZxys!4
int nCount = input.readInt(); *^ncb,1+i
nStartPos = new long[nCount]; &(-+?*A`E
nEndPos = new long[nCount]; !6\{q M
for(int i=0;i<nStartPos.length;i++) #-1 ;
{ N|?"=4Z?
nStartPos = input.readLong(); |/[?]`
nEndPos = input.readLong(); jTaEaX8+
} i}N'WV`!
input.close(); ([iMOE[D3
} 6<.Ma7)lA
catch(IOException e){e.printStackTrace ();} {LVii}<
catch(Exception e){e.printStackTrace ();} DY'D]*'7$
} >7B6iR6N
Eic/#j{4
DG}t!
private void processErrorCode(int nErrorCode) ?kX$Y{M}
{ L|EvI.f
System.err.println("Error Code : " + nErrorCode); R8Nr3M9 )
} F]@vmzr
i-~HT4iw
fB|rW~!v
//停止文件下载 r ,D T>
public void siteStop() Z\D!'FX
{ &]3_ .C
bStop = true; R}>xpU1
for(int i=0;i<nStartPos.length;i++) lX/s Q
fileSplitterFetch.splitterStop(); 4,!#E0
_@;t^j+l
f/&gR5
} R$k4}p
} (4o_\&
//负责部分文件的抓取 &eKnLGKD
**FileSplitterFetch.java 4UT%z}[!
*/ @ U xO!
package NetFox; ET;YAa*
u6Fm qK]Dj
'`&gSL.1a@
import java.io.*; AX,V* s
import java.net.*; S\b[Bq
8+5#FC7
}m0*w3
public class FileSplitterFetch extends Thread { WcqQR))n
1`J-|eH=Q
s9+Rq*Qd
String sURL; //File URL w=H
long nStartPos; //File Snippet Start Position L|pMq!@J
long nEndPos; //File Snippet End Position }7&.FV"
int nThreadID; //Thread's ID 88x_}M^Fnl
boolean bDownOver = false; //Downing is over i#]}k
boolean bStop = false; //Stop identical hAX@|G.
FileAccessI fileAccessI = null; //File Access interface /5 yjON{
~Gm<F .(+
67/JsL
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uNSaw['0j
{ 'ol8lIa.P
this.sURL = sURL; ?_)b[-N!
this.nStartPos = nStart; 2-=Ov@y2k!
this.nEndPos = nEnd; t66Cx
nThreadID = id; +9Q,[)e r
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V&)Jvx}^
} :0N}K}
eA q/[(
0T,uH
public void run() San3^uX
{ X)7_@,7
while(nStartPos < nEndPos && !bStop) N~NUBEKcp
{ BwOIdz%]OY
?-M?{De
wT\JA4
try{ fghw\\]3
URL url = new URL(sURL); rSu+zS7`X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iWu
httpConnection.setRequestProperty("User-Agent","NetFox"); +}3l$L'bY
String sProperty = "bytes="+nStartPos+"-"; bmCp:6
httpConnection.setRequestProperty("RANGE",sProperty); _EPfeh;
Utility.log(sProperty); .cks){\
709/'#- ^
h;TN$ /
InputStream input = httpConnection.getInputStream(); %lsRj)n
//logResponseHead(httpConnection); 2F7(Y)
CcCcuxtR
$'*q]]
byte[] b = new byte[1024]; U80h0t%
int nRead; m3T=x =
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c'|](vOd]
{ N 2XL5<
nStartPos += fileAccessI.write(b,0,nRead); E P3Vz8^
//if(nThreadID == 1) &&PXWR!%]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j+"w2
} IL>VH`D
{,+{,Ere
WuuF&0?8C
Utility.log("Thread " + nThreadID + " is over!"); ;yu#Bs
bDownOver = true; 0u) m9eg
//nPos = fileAccessI.write (b,0,nRead); 9%Eo<+myh
} AZ.$g?3w
catch(Exception e){e.printStackTrace ();} ;mT
} !!k^M"e2
} %* k`z#b
zm!M'|~@7
b#nI#!p'
//打印回应的头信息 "wy2u~
public void logResponseHead(HttpURLConnection con) [KL-T16
{ d{J@A;da
for(int i=1;;i++) uf^HDrr<L
{ ^c<8|lK L@
String header=con.getHeaderFieldKey(i); \Up~"q>Kb
if(header!=null) jiejs*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h! Bg}B~
Utility.log(header+" : "+con.getHeaderField(header)); Jmuyd\?,b
else O9P+S|hcY
break; b:5-0uxjs
} &\=Tm~
} Ht:\ z;cu
sW-0G$,|
.07"I7
public void splitterStop() +MZI\>
{ 9W0*|!tQ,+
bStop = true; )@ofczl6
} -=cm7/X
"}"/d(
g>@a
} dF[|9%)
182g6/,
%AN,cE*
/* )m#Y^
**FileAccess.java BhYvEbt
*//文件访问(定位，写) 3%+!qm
package NetFox; wfv\xHG
import java.io.*; Wco2i m
Q}G2f4
Rc:}%a%e
public class FileAccessI implements Serializable{ tz8fZ*n
z#Fel/L`O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ol41%q*
RandomAccessFile oSavedFile; .'&pw}F
long nPos; Yn[>Y)
[-VK!9pQ
G pI4QzR
public FileAccessI() throws IOException P6Y+ u
{ o">~ObR
this("",0); L}CU"
} Pro?xY$E)
up+0-!AH
'YB[4Q /0
public FileAccessI(String sName,long nPos) throws IOException v$0|\)E)
{ `kJ)E;v;3
oSavedFile = new RandomAccessFile(sName,"rw"); tewp-MKA
this.nPos = nPos; jC_'6sc`
oSavedFile.seek(nPos); m5iCvOP
} "b~C/-W I
#2s}s<Sc;
c+&Kq.~K
public synchronized int write(byte[] b,int nStart,int nLen) xhbN=L
{ $1"gFg
int n = -1; &BLCP d
try{ \HbZ~I-
oSavedFile.write(b,nStart,nLen); "o+?vx-
n = nLen; ]7Du/)$
} 5\# F5s}
catch(IOException e) l99Lxgx=
{ 6FNGyvBU
e.printStackTrace (); WM`3QJb
} J/'Fj?
Et!J*{s
>STthPO
return n; 1R3,Z8j'
} ed`"xm
I)V=$r{
lwq:0Rj@Q
} aSvv(iV
5PO_qr=Hx
O\.^H/
/* Ny2 Z <TW
**SiteInfoBean.java b'\Q/;oz>
*/ #0r~/gW
package NetFox; q4[8\Ua
>2znn&gZ
##6\~!P
public class SiteInfoBean { a$|U4Eqo
uVUU1@
a~7D4G
private String sSiteURL; //Site's URL c'i5,\#X
private String sFilePath; //Saved File's Path gLX<>|)*
private String sFileName; //Saved File's Name J)YlG*
private int nSplitter; //Count of Splited Downloading File 8{jXSCP#
6?F88;L
BQ0?B*yqd
public SiteInfoBean() MvpJ0Y (
{//nSplitter的缺省值为5 2{&A)Z!I
//default value of nSplitter is 5 ;[::&qf
this("","","",5); j**[[
} AB'+6QU9k
,!l_
\Ip)Lm0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k`m7j[A]l
{ h.X4x2(.
sSiteURL= sURL; @e)}#kN.
sFilePath = sPath; $\BYN=#
sFileName = sName; [Kwj 7q`
this.nSplitter = nSpiltter; X(ph$,[
gsyOf*Q$
J#..xJ?XRD
} rw'+2\
PyQ.B*JJ
op}!1y$9P
public String getSSiteURL() L~6%Fi&n4
{ \P.h;|u
return sSiteURL; |/gt;H~:
} C#U(POA
n4kq=Z%
wD9K\%jIr!
public void setSSiteURL(String value) UTkPA2x
{ V\Cl""`XN
sSiteURL = value; +yP!7]
} 0VNLhM(LM
6YM X7G]
:.x(( FU
public String getSFilePath() >38>R0k35
{ z;qDl%AF
return sFilePath; n-ffX*zA(
} |Vpp'ipr
x?wvS]EBg
t*(bF[?
public void setSFilePath(String value) 7S{qo&j'
{ .#yg=t1C
sFilePath = value; _@ao$)q{J
} p1KhI;^
b&rBWp0#
$f =`fPo
public String getSFileName() rt+4-WuK>
{ Ce}`z L
return sFileName; :TQp,CEa
} $@z77td3
<[db)r~c
&O'W+4FAc
public void setSFileName(String value) Uc tlE>X`
{ *$eH3nn6g
sFileName = value; 6eSo.@*l
} PF~@@j
Clum m@z;#
layxtECP(
public int getNSplitter() d {!P c<
{ V"#0\|]m
return nSplitter; Jh\KVmfXN
} ^EUR#~b5iy
Xw4Eti._D
p'h'Cz
public void setNSplitter(int nCount) Usf@kVQ
{ [K4cxqlfk
nSplitter = nCount; >#G%2Vp
} G+c&e:ip<
} :4{ `c.S
*Dp&;,b
eHgr"f*7
/* e)e(f"t6Q
**Utility.java H:(B^uH
*/ .V;,6Vq
package NetFox; +p\E%<uQ
>|SIqB<%:
pf8'xdExH)
public class Utility { _`?0w#>0
{vD$odi
o9xc$hX}
public Utility() Z|qI[uiO
{ }U7IMONU
2*g2UP
s\d3u`G
} I=L["]
VN)WBv
//线程睡眠 ROkwjw
public static void sleep(int nSecond) vC,FE )'
{ *8)?ZZMM
try{ iF`_-t/k
Thread.sleep(nSecond); v/ry" W
} sPK]:iC
catch(Exception e) RC7F/|w.z
{ *9n[#2sM<
e.printStackTrace (); =o(}=T>:"
} @ 51!3jeu
} dg|+?M^9`
@JSWqi>
//日志 $PMr)U
public static void log(String sMsg) vJ0v6\
{ S\Z*7j3;M
System.err.println(sMsg); ^?e[$}
} <);j5)/
tM5(&cQ!d
@6ckB (
public static void log(int sMsg) Y's=31G@
{ jO"/5x26
System.err.println(sMsg); i<S\x
} %>K(IRpMW
} |e8A)xM]wC
6ud?US(
$idToOkw
/* zDYJe_m ~
**TestMethod.java 7NEOaX(J9
*/ 0^{Tq0Ri[
package NetFox; f.ua,,P.
9@t&jznt<
23LG)or.JC
public class TestMethod { M]V j
CMC p7-v
<c@dE
public TestMethod() tDAX pi(
{ ///xx/weblogic60b2_win.exe T>|+cg
try{ ^/2O_C
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $I`,nN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '\H & EJ'
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2s2KI=6
fileFetch.start(); -X EK[
} aQhT*OT{Q
catch(Exception e){e.printStackTrace ();} v-$X1s
(Vey]J
AJ 0Bb7
} \(Dm\7Q.
TbMlYf]It
"`K73M,c?9
public static void main(String[] args) 6wiuNGZb
{ U&kdR+dB
new TestMethod(); 0NsPo
} Pw|/PfG
} };(2 na
点击下载更多相关资料