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)); 8Jy1=R*S
} \%4+mgiD
for(int i=0;i<nEndPos.length-1;i++) :#&U95EC0
{ T=p}By3a
nEndPos = nStartPos[i+1]; ~E6+2t*
} @Qsg.9N3K
nEndPos[nEndPos.length-1] = nFileLength; &40JN}
} [Ey%uh 6*
} &LxzAL,3!
/jL{JF>I
RVKaqJ0e<
//启动子线程 HI?~t|[y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; JU%yqXO
for(int i=0;i<nStartPos.length;i++) 4oaP"T@6
{ X9`C2fyVd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ThQEQ6y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +uGP(ONY
nStartPos,nEndPos,i); #]\G*>{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [;LPeO
fileSplitterFetch.start(); +fQ$~vr{'
} ^5@"|m1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b+j_EA_b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Nm:<rI,^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9kg>)ty@
nEndPos = " + nFileLength); Hr,lA(
// fileSplitterFetch[nPos.length-1].start(); m=l3O:~J
C%7)sLWjJS
]}Hv,a
//等待子线程结束 ^d$e^cU
//int count = 0; U &k3
//是否结束while循环 Pc ?G^ Xol
boolean breakWhile = false; F1[[fH
3\l9Sf=M|
]~ 8N
while(!bStop) <.B> LU
{ mt]YY<l
write_nPos(); <W|{)U?p
Utility.sleep(500); kX .1#%Ex
breakWhile = true; .;v'oR1x5
A(sx5Ynp
<^c0bY1
for(int i=0;i<nStartPos.length;i++) (2\ekct ^
{ ..{^"`FQ
if(!fileSplitterFetch.bDownOver) 5<8>G?Y
{ LK}eU,m=
breakWhile = false; :<3;7R'5
break; hfa_M[#Q-
} ?-v?SN#
} 5:3$VWLa <
if(breakWhile) NbMH@6%E
break; =y/Lbe}:
mpJ_VS`
5*'N Q010
//count++; NW Qu-]P
//if(count>4) 7Ki7N{Kt
// siteStop(); t7%Bv+Uo
} D(?#oCCA
7#*CWh1BNO
qGUe0(
System.err.println("文件下载结束！"); APm[)vw#f
} 0`zq*OQ
catch(Exception e){e.printStackTrace ();} yAkN2
} WZ-{K"56
I}3K,w/7mi
?Og;W9i
//获得文件长度 9e*poG
public long getFileSize() f3|=T8"t
{ ptfADG
int nFileLength = -1; g+F_M
try{ a m%{M7":7
URL url = new URL(siteInfoBean.getSSiteURL()); 56aJE .?<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $)a5;--W
httpConnection.setRequestProperty("User-Agent","NetFox"); @D{[Hj`<
y`Y}P1y*
pMrfi}esx
int responseCode=httpConnection.getResponseCode(); QCnVZ" !(
if(responseCode>=400) 82l";;n4p
{ Mi-9sW
processErrorCode(responseCode); +& Qqu`)?F
return -2; //-2 represent access is error @2O\M ,g5
} 6%axbB
K?eo)|4)DB
g 0=t9J
String sHeader; v65r@)\`
;:1mv
ew~FN
for(int i=1;;i++) :fUmMta
{ ?7s
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uf3 gVS_h=
//Utility.log(in.readLine()); ^el:)$
sHeader=httpConnection.getHeaderFieldKey(i); KwyXM9h6=
if(sHeader!=null) qA[}\8}h
{ Jrl xa3 [
if(sHeader.equals("Content-Length")) _Y~?.hs^
{ |mX8fRh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I<#kw)W!
break; '1*MiFxKq
} Dne&YVF9V
} <VPtbM@(m
else 1yf&ck1R
break; H[oi? {L
} ?RyvM_(N6
} U:(t9NX b
catch(IOException e){e.printStackTrace ();} ?+_"2XY
catch(Exception e){e.printStackTrace ();} (ZJ_&8C#
> [7vXm4
3EdPKM j&
Utility.log(nFileLength); N/p_6GYMa
3M`J.>
o)DKP>IM#
return nFileLength; @n3PCH6:Ao
} BC+qeocg
IS~oyFS
^.7xu/T
//保存下载信息（文件指针位置） u[@*}|uXM
private void write_nPos() %*hBrjbj
{ B dUyI_Ks:
try{ 6<R U~Gh
output = new DataOutputStream(new FileOutputStream(tmpFile)); X*&r/=
output.writeInt(nStartPos.length); `^x^= og'
for(int i=0;i<nStartPos.length;i++) M,P_xkLp
{ &v88xs
// output.writeLong(nPos); b1"wQM9
output.writeLong(fileSplitterFetch.nStartPos); qKXn=J/0tA
output.writeLong(fileSplitterFetch.nEndPos); 8iB}a\]B
} e V#H"fM
output.close(); ^ TS\x/P
} lRq!|.C
catch(IOException e){e.printStackTrace ();} vJs/ett
catch(Exception e){e.printStackTrace ();} 7#`:m|$
} O5w\oDhMb
*{bqHMd4L
7dRU7p>
//读取保存的下载信息（文件指针位置） 12E"6E)
private void read_nPos() }K\_N]#6n
{ u-$AFSt
try{ IG\\RYr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /e,lD)
int nCount = input.readInt(); Hqk2W*UTl
nStartPos = new long[nCount]; Bf.RYLsh6
nEndPos = new long[nCount]; s Y,3
for(int i=0;i<nStartPos.length;i++) l;fH5z
{ 'lF|F+8
nStartPos = input.readLong(); c4|.!AQ>
nEndPos = input.readLong(); 6Xa2A6
} a &j?"o
input.close(); R:E:Y|&#
} (`N/1}vk
catch(IOException e){e.printStackTrace ();} 9cQSS'`F
catch(Exception e){e.printStackTrace ();} cW2:D$Pe
} 3ml|`S
Q]HRg4r
@QEVl
private void processErrorCode(int nErrorCode) @9L9c
{ _gHJ4(?w
System.err.println("Error Code : " + nErrorCode); =W6P>r_
} {+ m)*3~w
UTz;Sw?~hw
cjL!$OE6
//停止文件下载 #'[ f^xgJ
public void siteStop() %2{E'^#)p-
{ kF5}S8B
bStop = true; mMR[(
for(int i=0;i<nStartPos.length;i++) z t1Q_;
fileSplitterFetch.splitterStop(); Mm5l>D'c
*VpQ("
]PFc8qv{
} fAK
} +1Uw<~
//负责部分文件的抓取 !(]|!F[m
**FileSplitterFetch.java S'WmPv
*/ _MR2,mC
package NetFox; $]vR,E
{>:2Ff]O:
J]%P fWV
import java.io.*; `U1"WcN
import java.net.*; )gR&Ms4
0Ec -/
1Dbe0u
public class FileSplitterFetch extends Thread { HTC7fS
I|.B-$gH
V3-LVgM%
String sURL; //File URL a'|0e]
long nStartPos; //File Snippet Start Position k;)L-ge9
long nEndPos; //File Snippet End Position D -jew&B
int nThreadID; //Thread's ID ,UP6.C14
boolean bDownOver = false; //Downing is over R'{V&H^Z
boolean bStop = false; //Stop identical :+YFO.7
FileAccessI fileAccessI = null; //File Access interface lfhB2^^
ZE :oK
?vhW`LXNB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rScmUt
{ f7`y*9^
this.sURL = sURL; ELm#
this.nStartPos = nStart; N\p3*#M
this.nEndPos = nEnd; BKIt,7j
nThreadID = id; W&"FejD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Mfgd;FsX#
} ZK;HW
' ft |
h_cZ&P|
public void run() F2u{Wzr_@
{ 2@ad!h
while(nStartPos < nEndPos && !bStop) SZgH0W("L
{ XW19hG
<%!@cE+y
;%U`P8b!
try{ ^PDa
URL url = new URL(sURL); 0$UE|yDs>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z6Mh`:7
httpConnection.setRequestProperty("User-Agent","NetFox"); 6Us#4 v,
String sProperty = "bytes="+nStartPos+"-"; ]6%| L
httpConnection.setRequestProperty("RANGE",sProperty); 3A+d8fwi
Utility.log(sProperty); `527vK 6
!6kLg1
8\[6z0+;
InputStream input = httpConnection.getInputStream(); &BQ`4j~.
//logResponseHead(httpConnection); %9M_*]
5r.{vQ
4WNWn#M
byte[] b = new byte[1024]; b&!X#3(KT
int nRead; KQEnC`Nz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Oh|Hy/&6W
{ ?&N JN/+%
nStartPos += fileAccessI.write(b,0,nRead); _xbVAI4
//if(nThreadID == 1) wc ^z9y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S3 &L
} TEY%OIzU+
M*t{?o/t;
RhYf+?2
Utility.log("Thread " + nThreadID + " is over!"); nlJxF5/
bDownOver = true; Fd3V5h
//nPos = fileAccessI.write (b,0,nRead); N5g!,3
} 0{ \AP<
catch(Exception e){e.printStackTrace ();} Q|;8\5
} iLgWzA
} :sJVklK
Xbfn@7m
ab6KK$s
//打印回应的头信息 c$>Tfa'H
public void logResponseHead(HttpURLConnection con) h_H$+!Nzb
{ >d_O0a*W-
for(int i=1;;i++) aQcJjF5x
{ AuWEy-q?
String header=con.getHeaderFieldKey(i); p6|0JBm
if(header!=null) mI}1si=$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @<l7"y;\
Utility.log(header+" : "+con.getHeaderField(header)); uP<tP:
else ZMoN
break; q*52|?
} @<;0h|
} O9jqeF`L=
4R.rSsAH
FL-sXg
public void splitterStop() }ufH![|[r
{ Kk-A?ju@g
bStop = true; A[^fG_l4
} *GD?d2.6j
R{u/r%
}fdo Aid~
} L-vy,[9)[*
)nQA) uz
j#zUO&Q@
/* P6@(nGgK<
**FileAccess.java !Yd7&#s
*//文件访问(定位，写) !bRoNP
package NetFox; ?X~Keb
import java.io.*; 94\k++kc
?o?~Df&
\$W>@w0
public class FileAccessI implements Serializable{ 0escp~\Z
tWT@%(2~0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {L4ta~2/T
RandomAccessFile oSavedFile; $0=f9+@5
long nPos; N8_ c%6GE
B^Fe.ty
1>|2B&_^
public FileAccessI() throws IOException 5Z@OgR
{ #Fm,mO$v
this("",0); \%g# __\
} t&*X~(Yb!
-YPUrU[)
:/A3l=}iV
public FileAccessI(String sName,long nPos) throws IOException 7&-B6Y4
{ G&y< lh
oSavedFile = new RandomAccessFile(sName,"rw"); D% v{[KY
this.nPos = nPos; krnxM7y
oSavedFile.seek(nPos); "Y-_83
} f_I6g uDPz
!#xk?LyB
[Wf%iwB
public synchronized int write(byte[] b,int nStart,int nLen) s"gNHp.oF
{ 1CXO=Q
int n = -1; *.qm+#8W
try{ }V:ZGP#!'
oSavedFile.write(b,nStart,nLen); >PHin%#
n = nLen; C+tB$yahO
} RE6d&#N
catch(IOException e) ]6#bp,
{ HtFc+%=
e.printStackTrace (); wA$ JDf)Vg
} jJc:%h$|2
sbqAjm}
KsVN<eR{
return n; J'4Pp<
} p(vmMWR!
WOkAma-
O1xK\ogv
} _ x8gEK8
2nz^%pLT
"=H(\V
/* tr?U/YG
**SiteInfoBean.java x6N)T4J(
*/ *,az`U
package NetFox; z'"e|)
Es]:-TR
!:BmDX[<n
public class SiteInfoBean { bSJ@ 5qS
'/O >#1
^W#161&
private String sSiteURL; //Site's URL Z/G`8|A
private String sFilePath; //Saved File's Path 8=kIN-l_
private String sFileName; //Saved File's Name #X 1 GL
private int nSplitter; //Count of Splited Downloading File X?f\j"v
\P~h0zg?
\%BII>VS
public SiteInfoBean() R^*%yjy9
{//nSplitter的缺省值为5 dBRK6hFC
//default value of nSplitter is 5 j{&*]QTN
this("","","",5); >>nOS]UL
} e)BU6m%
fmgXh)=
CqFk(Td9-D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^]n:/kZ5"[
{ H"5=z7w
sSiteURL= sURL; 2-$O$&s.
sFilePath = sPath; X^o0t^
sFileName = sName; 1Y+g^Z;G
this.nSplitter = nSpiltter; U,Q
IEmjWw4
0#y i5U
} &) qs0
6Cj$x.-K
(baBi9<P=
public String getSSiteURL() [%LIW%t|
{ X:2)C-l?
return sSiteURL; M4}b lh#
} Wd>gOE
nVyV]'-z
1[:tiTG|C
public void setSSiteURL(String value) Bcl6n@{2f
{ r7FFZNs!
sSiteURL = value; ^!A@:}t>
} A<p6]#t#X)
&"6%D|Z0
uz;zmK
public String getSFilePath() HRg< f= oz
{ XMlcY;W
return sFilePath; Vw";< <0HZ
} |V-)3#c
eKvQS}11
Qv B%X)J
public void setSFilePath(String value) Lq#$q>!K
{ )(V!& w6
sFilePath = value; \AY*x=PF
} #-7w|
UPcx xtC
{?uG] G7
public String getSFileName() x5(B(V@b
{ w%?6s3
return sFileName; ]I:h4hgw
} |R3A$r#-
M _e^KF
!n3J6%b9y/
public void setSFileName(String value) FA$1&Fu3Y
{ (5h+b_eB
sFileName = value; fI }v}L^
} l<-0@(x)
~]78R!HJ
OM (D@up
public int getNSplitter() lG R6S
{ Yq0jw&v
return nSplitter; i1^#TC$x
} T{4Ru6[
?TMrnR/d
#xNXCBl]O
public void setNSplitter(int nCount) nO;t5d
{ l'FNp
nSplitter = nCount; EF8'ycJk+
} ZnZ`/zNO
} xB|?}uS-
RGz NZc
hM[QR'\QS
/* ;S}_/'
**Utility.java f[+N=vr
*/ Q}|QgN
package NetFox; (4"Azo*~![
dFzlcKFFD
M&ec%<lM
public class Utility { ]#P>wW
Q|Go7MQZ@k
<~iA{sY)O
public Utility() 'w`3( ':=
{ &k@r23V7r
|yYu!+U
2>h.K/pC
} lQl
p?Jx2(%m
//线程睡眠 |n*<H|
public static void sleep(int nSecond) j7v?NY
{ ZE4xF8
try{ $94l('B6H
Thread.sleep(nSecond); ZuVes?&j
} 3-U@==:T
catch(Exception e) ST25RJC
{ "FH03 9
e.printStackTrace (); yGX"1Fb?;x
} Pj7n_&*/
} a6epew!2
+kZW:t!-
//日志 HV\l86}
public static void log(String sMsg) 9xM7X?
{ /8"9sf*
System.err.println(sMsg); NTy0NH
} |^T?5=&Kt
y)D7!s
AA~6r[*~
public static void log(int sMsg) 5~E'21hJ
{ B<6Ye9zuG
System.err.println(sMsg); \zv?r:1t
} d!#qBn$*[
} THf*<|
+9[s(E?SY
q<>aZ|r
/* ht5eb"c+8
**TestMethod.java tp?< e
*/ `AcT}.u
package NetFox; 2-x#|9
0pl |
sEm064
public class TestMethod { yVl?gGgh
_|} GhdYE
J)"g`)\2+
public TestMethod() 7^*[XH
{ ///xx/weblogic60b2_win.exe x/^,{RrPk
try{ 61=D&lb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /G& %T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^Uq"hT(41
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,/6 aA7(
fileFetch.start(); F2Nb]f
} Y!nxHRE
catch(Exception e){e.printStackTrace ();} @WfX{485
w;4FN'
\'.#of
} NZ=`iA8)X
P/;d|M(
y;1l].L
public static void main(String[] args) 8e*1L:oB!
{ h4lrt
new TestMethod(); ZA Xw=O5
} /R!/)sg
} 3 F ke#t
点击下载更多相关资料