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)); 1D pRm(
} t'F_1P^*/
for(int i=0;i<nEndPos.length-1;i++) R>YDn|cWI
{ .-(s`2
nEndPos = nStartPos[i+1]; .eSMI!Y=
} nU6WT|
nEndPos[nEndPos.length-1] = nFileLength; <X{hW^??)
} f/VrenZ_
} NIQX?|;b{
YyZ>w2_MTi
h"-}BjL
//启动子线程 BW61WH?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; tUp'cG
for(int i=0;i<nStartPos.length;i++) 3?"JFfYU,'
{ WRWcB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NSPa3NE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;~>E^0M
nStartPos,nEndPos,i); )= ,Lfj8x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Yom,{;Bv
fileSplitterFetch.start(); =:!$'q:
} N]k(8K
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zz4.gkU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xTJ-v/t3<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", m#(tBfH[
nEndPos = " + nFileLength); i~k9s
// fileSplitterFetch[nPos.length-1].start(); R&OqmhT!
\*_@`1m
_v+mjDdQ
//等待子线程结束 .skR4f,h
//int count = 0; -C7IUat<
//是否结束while循环 t!g9,xG<X
boolean breakWhile = false; Px>Gc:!>
bwm?\l.A
6#JdQ[IP6
while(!bStop) G|p3NhLgO=
{ ~4Gs\U:!Q
write_nPos(); kUdl2["MZ
Utility.sleep(500); A!K/92[#@
breakWhile = true; Eoj 2l&\
'Gw;@[
CulU?-[i
for(int i=0;i<nStartPos.length;i++) \rw/d5.
{ iE|qU_2Y
if(!fileSplitterFetch.bDownOver) S!<1CFh
{ 8"#Ix1#
breakWhile = false; b$24${*'
break; KXgC]IO~
} &tULSp@J
} q]\bJV^/U
if(breakWhile) 2g6G\F
break; F=29"1 ._
*hT1_
u7e g:0Y
//count++; e*Gm()Vu,
//if(count>4) bHr2LhQCN
// siteStop(); t ._PS3
} R7L:U+*V"
btfjmR<Tp
ohdWEU,
System.err.println("文件下载结束！"); K$H>/*&'~
} `FP)-^A8
catch(Exception e){e.printStackTrace ();} Dm=Em-ST6
} G n_AXN
nC3U%*l
uh~/ybR
//获得文件长度 P~)ndaQ
public long getFileSize() <&?gpRK
{ .Z!!x
int nFileLength = -1; RsYn6ozb
try{ %G<!&E!0h
URL url = new URL(siteInfoBean.getSSiteURL()); QL>G-Rp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G36}4
httpConnection.setRequestProperty("User-Agent","NetFox"); U#O6l-xe]
(;V=A4F-D
w>IYrSaa>
int responseCode=httpConnection.getResponseCode(); FT1h\K|a
if(responseCode>=400) b[^=GF>e
{ KUdpOMYX
processErrorCode(responseCode); >+[uV^2[
return -2; //-2 represent access is error ZD9UE3-
} ~h~K"GbC?
Fr}e-a
Y2 &N#~l*
String sHeader; T4dYC'z
S^@I4Z
mGjxc}
for(int i=1;;i++) N#;k;Z'iL
{ r@&d88U:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y@;4F n/
//Utility.log(in.readLine()); oh '\,zpL
sHeader=httpConnection.getHeaderFieldKey(i); LF'M!C9|
if(sHeader!=null) 1Ftl1uf
{ JD^&d~n_
if(sHeader.equals("Content-Length")) :<OInKE>Cx
{ y(K?mtQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !@ml^&hP
break; aW8Bx\q
} ?-g=Rfpag
} y)W.xR
else Ge+&C RhyX
break; W^2Q"c#7F
} 4]N`pD5
} !8"516!d|p
catch(IOException e){e.printStackTrace ();} H}NW?
catch(Exception e){e.printStackTrace ();} C7(kV{h$d
Jy'ge4]3
H!Y`?Rc
Utility.log(nFileLength); eH2.,wY1
%d+:0.+`n
_/"m0/,
return nFileLength; ?-,v0#
} V8>%$O sw
H1uNlPT
_wWh7'u~G
//保存下载信息（文件指针位置） b;&J2:`
private void write_nPos() ]@op
{ (9h{7<wD`
try{ fW Vd[zuD4
output = new DataOutputStream(new FileOutputStream(tmpFile)); D-.XSIEMu
output.writeInt(nStartPos.length); Ox"4 y
for(int i=0;i<nStartPos.length;i++) ?aInn:FE
{ k/vE|
// output.writeLong(nPos); Q)}sX6TB
output.writeLong(fileSplitterFetch.nStartPos); hq.z:D
output.writeLong(fileSplitterFetch.nEndPos); cLH|;
} x.r~e)x=
output.close(); t;9f7~
} [8/E ;h
catch(IOException e){e.printStackTrace ();} 3LZ0EYVL
catch(Exception e){e.printStackTrace ();} ^f{+p*i}:
} tvptawA.
Hw34wQX
s> JmLtT
//读取保存的下载信息（文件指针位置） vJ$#m_aa
private void read_nPos() `j088<?j
{ yzhr"5_
try{ o}p6qB=;1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YJ]]6 K+
int nCount = input.readInt(); !!ZNemXct$
nStartPos = new long[nCount]; KIdlndGs
nEndPos = new long[nCount]; /<Cl\q2 A
for(int i=0;i<nStartPos.length;i++) tFvti5
{ :8U=L'4
nStartPos = input.readLong(); hq/k}Y
nEndPos = input.readLong(); 6hSj)
} SX|b0S,
input.close(); $kJvPwRO
} GLA,,i'i9
catch(IOException e){e.printStackTrace ();} @R>4b
catch(Exception e){e.printStackTrace ();} +nRO<
} -p`hevRr
KcVCA
Wx"bW ICc
private void processErrorCode(int nErrorCode) b/oJ[Vf
{ pYJv|`+
System.err.println("Error Code : " + nErrorCode); &C3J6uCm+
} #rzq9}9tB
wH[@#UP3l
v\:>} <gc
//停止文件下载 >Vc_.dR)E
public void siteStop() Py6c=&*
{ Zi/l.=9n
bStop = true; $O&P@8:Z
for(int i=0;i<nStartPos.length;i++) o[^%0uVF
fileSplitterFetch.splitterStop(); 6}2vn5 E//
,U2 /J
J0w[vrs&]
} lyKV^7}
} Mw7 ~:O`
//负责部分文件的抓取 ,;C92XY
**FileSplitterFetch.java a3 wUB
*/ E0}`+x
package NetFox; [i.2lt#]
N\DEY]
GAbX.9[V
import java.io.*; v')Fq[H
import java.net.*; }4Lv-9s,
$k*E^~qT
[g/Hf(&
public class FileSplitterFetch extends Thread { !1!;}uzt
\uQB%yMoz
A[v]^pv'
String sURL; //File URL t/HMJ
long nStartPos; //File Snippet Start Position Uf{cUY,j_
long nEndPos; //File Snippet End Position ]7v-qd
int nThreadID; //Thread's ID _h7!
boolean bDownOver = false; //Downing is over +Tde#T&[
boolean bStop = false; //Stop identical ?)-*&1cv
FileAccessI fileAccessI = null; //File Access interface eh nN
Afo(! v
|h(!CFR
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gA~BhDS
{ (w?@qs!
this.sURL = sURL; b&~rZ
this.nStartPos = nStart; 83:m7;
this.nEndPos = nEnd; nX<!n\J T
nThreadID = id; nK1XJp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Fkj\U^G
} +wwpaR`
9*RfOdnNe
=(K;z9OR
public void run() m C_v!nL.
{ tTe\#o`
while(nStartPos < nEndPos && !bStop) |HI=ykfI
{ EbuOPa
q .nsGbl
[3;J,P=&
try{ pNr3u
URL url = new URL(sURL); I5>HB;Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w<&Nn`V
httpConnection.setRequestProperty("User-Agent","NetFox"); ]K?z|&N|HK
String sProperty = "bytes="+nStartPos+"-"; 4vPQuk!
httpConnection.setRequestProperty("RANGE",sProperty); EU TTeFp
Utility.log(sProperty); beEdH>
`,tv&siSA
/!oi`8D
InputStream input = httpConnection.getInputStream(); /A[AHJ<[?
//logResponseHead(httpConnection); J %jfuj
AnG/A!G
AF ZHS\
byte[] b = new byte[1024]; [Nr6qxWg
int nRead; .VuZ=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (A\qZtnyl
{ ]IXKoJUf
nStartPos += fileAccessI.write(b,0,nRead); PDvqA{
//if(nThreadID == 1) 1wuLw Ad
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <a2t"rc
} D$;mur'
1[D~Eep
h&L+Qx
Utility.log("Thread " + nThreadID + " is over!"); oat*ORL
bDownOver = true; 'g^;_=^G
//nPos = fileAccessI.write (b,0,nRead); 0wB ?U~
} BQ,]]}e43z
catch(Exception e){e.printStackTrace ();} p82&X+v/p
} a"EP`
} 8#2PJHl;
L{N9h1]
KR%p*Nh+C
//打印回应的头信息 HviL4iO
public void logResponseHead(HttpURLConnection con) >&RpfE[
{ \gki!!HQ
for(int i=1;;i++) Nj*J~&6G
{ U:~O^
String header=con.getHeaderFieldKey(i); Xgn^)+V:
if(header!=null) 5@P2Z]Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "X's>uM
Utility.log(header+" : "+con.getHeaderField(header)); >e($T!}Z
else :g}WN
break; Ti#2D3
} ,E$^i~OO
} X_Is#&6;
}I}RqD:`
x,@cU}D
public void splitterStop() ? Sj,HLo@U
{ [m?eSq6e2b
bStop = true; {[61LQ6V9
} UMpC2)5
)i0\U
Ra&HzK?
} WM*[+8h
|0ACapp!
c>:}~.~T
/* o>311(:
**FileAccess.java L0qo/6|C
*//文件访问(定位，写) Z9cch-u~
package NetFox; @ T'!;)
import java.io.*; Dh BUMDoB
.8uJ%'$)
`fu(
public class FileAccessI implements Serializable{ BOrfKtG\
~zi6wu(3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R#`hT
RandomAccessFile oSavedFile; q%bNT
long nPos; L:IaJ?+?
fJn;|'H!
l6:k|hrm;
public FileAccessI() throws IOException D!Owm&We
{ Ry,_%j3
this("",0); aU<0<Dx
} v2gK(&?
$fPf/yQmC
ba1zu|@w
public FileAccessI(String sName,long nPos) throws IOException ah>;wW!6/
{ ,u-i9`B
oSavedFile = new RandomAccessFile(sName,"rw"); fCJ:QK!
this.nPos = nPos; s+2\uMwf*
oSavedFile.seek(nPos); J1cD)nM<A
} XG@_Lcv*
]QJLES
L}P<iB
public synchronized int write(byte[] b,int nStart,int nLen) |F-_YR
{ [a53H$`\5
int n = -1; ZtlF]k:MV
try{ e]!C Aj7uS
oSavedFile.write(b,nStart,nLen); P+:FiVj@~
n = nLen; &1ASWllD
} kn 5q1^
catch(IOException e) T#DJQ"$
{ mLd=+&M
e.printStackTrace (); UtIwrR[
} ;gcQ9L
ib/B!?/
'vgw>\X(
return n; ?y>xC|kt
} eG72=l)Mz
yeFt0\=H
$u|p(E:*
} /FJAI
KXL]Qw FN
#*BcO-N
/* QKL5! L9`
**SiteInfoBean.java 30-XFl
*/ #.$p7]
package NetFox; rtS(iD@B"
YT+fOndjaF
UO5^4
public class SiteInfoBean { ,}2M'DSWa
x|<rt966A
>:4}OylhM
private String sSiteURL; //Site's URL tQ< ou,
private String sFilePath; //Saved File's Path T)6p,l
private String sFileName; //Saved File's Name BEPeK
private int nSplitter; //Count of Splited Downloading File ;Z-xum{
\m1r(*Ar
lsCD%P
public SiteInfoBean() wA|m/SZx
{//nSplitter的缺省值为5 *>n<7T0
//default value of nSplitter is 5 ~P 1(%FZ
this("","","",5); K||9m+
} ^&am]W;T
^*#5iT8/
tj;<Z.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NC)Iu
{ TFb9gOTJ
sSiteURL= sURL; +yiGZV/X
sFilePath = sPath; rBye%rQRq
sFileName = sName; 1/c7((]7(,
this.nSplitter = nSpiltter; mg[=~&J^
<_=a1x
P#\L6EO.
} -^=gQ7f9
r"x|]nvg^
}o0R`15dA
public String getSSiteURL() i64a]=
{ "1$OPt5
return sSiteURL; {(U?)4@
} 8`Q8Mct$<
q]T{g*lT
}i!hzkK#
public void setSSiteURL(String value) F&<si:}KB
{ /B.\6
sSiteURL = value; wqx@/--E(
} 8G; t[9
?DzKqsS'
x* *]@v"g
public String getSFilePath() S75wtz)e
{ hn{]Q@(I
return sFilePath; >0~|iRySi
} m{9m.~d
\< <u
1q0DOf]!T
public void setSFilePath(String value) RJYuyB
{ fdc ?`4
sFilePath = value; \-a^8{.^E
} -"YQo
|'9%vtbM
TUHC[#Vb?
public String getSFileName() f]L`^WU
{ /5 B{szf
return sFileName; 9G_bM(q'^2
} *&9_+F8ly
<e-9We."
0+jR,5|
public void setSFileName(String value) :CH "cbo
{ yoGe^gar
sFileName = value; ~UA-GWb
} X1?7}VO
=kH7
DygMavA.
public int getNSplitter() [g`9C!P-G
{ e` Z;}& ,
return nSplitter; .I$Q3%s
} )XV|D
P+ONQN|
j|gQe .,1
public void setNSplitter(int nCount) 28[hp[<
{ VHwb 7f]gq
nSplitter = nCount; B38_1X7
} EtvZk9d6h*
} vM!lL6T:
o%XAw
kW0|\
/* DP ,owk
**Utility.java ,*$L_itL
*/ `WQz_}TqB
package NetFox; /yPFts_q
:@x24wN/
N7Vv"o
public class Utility { l5_RG,O0A
0h/gqlTK1
T;K@3]FbX
public Utility() E/2kX3}
{ O32p8AxEz
F^.w:ad9<
@{*z1{
} o7 ^t- L
"| cNY_$&s
//线程睡眠 rOQ@(aUAZ
public static void sleep(int nSecond) )'3(=F$+l
{ ATl.Qku@
try{ 9Jd{HI=
Thread.sleep(nSecond); BOClMeA4
} dZcRLLR
catch(Exception e) RnC96"";R.
{ s ;EwAd(
e.printStackTrace (); /.B7y(
} 0t[|3A~Q
} 2z+Vt_%
kDI(Y=Fg
//日志 X3&-kU
public static void log(String sMsg) t`=TonLb8
{ PDQC^2Z
System.err.println(sMsg); T n.Cj5
} ,{==f7|w
c-3-,pyM_T
Ks'msSMC
public static void log(int sMsg) reseu*5
{ h&@A'om~
System.err.println(sMsg); ZGO%lkZ.
} 0?OTa<c
} $I*ye+a*{q
.<&o,D
aVkgE>
/* NwPGH=V
**TestMethod.java j#L"fW^GM
*/ s|B
package NetFox; 4M4Y2fBH
DP{kin"4I
K8`Jl=}z%&
public class TestMethod { JLgk?
!SRElb A;i
)y>o;^5'
public TestMethod() qQK0s*^W
{ ///xx/weblogic60b2_win.exe =nPIGI72VO
try{ Mh [TZfV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IIrh|>d_7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?pSb,kN}'
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1./uJB/
fileFetch.start(); (ndXz
} u'Ja9m1
catch(Exception e){e.printStackTrace ();} 3ht>eaHi
n^vL9n_N
fLkZ'~e!
} N zrHWVD
LpRl!\FY$
#9{N[t
public static void main(String[] args) (=#[om(A
{ u\-WArntc
new TestMethod(); $Ro]]NUz|
} Mn$w_Z?
} I ACpUB
点击下载更多相关资料