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)); 5>e<|@2 X
} s)3CosU
for(int i=0;i<nEndPos.length-1;i++) 1)~9Eku6K
{ s/>0gu]A8
nEndPos = nStartPos[i+1]; ; %AgKgV
} dpge:Qhr
nEndPos[nEndPos.length-1] = nFileLength; 1W0[|Hf2v*
} Yc)Dx3
} hWn-[w/l_
`z/p,. u
Rm,>6bQx
//启动子线程 pFu!$.Fr
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Mw+ l>92
for(int i=0;i<nStartPos.length;i++) r-WX("Vvh
{ j~+(#|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m,6u+Z,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vz:VegS
nStartPos,nEndPos,i); &0ymAf5R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KL(sVj^e
fileSplitterFetch.start(); gd%Ho8,T
} })PU`?f
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RMs8aZCa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )"tM[~e`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o?= &kx
nEndPos = " + nFileLength); 5[*8CY
// fileSplitterFetch[nPos.length-1].start(); Z;R/!Py.
_D+J3d(Pjk
m^RO*n.
//等待子线程结束 ?%Q=l;W.
//int count = 0; .k up[d(
//是否结束while循环 Ya<V@qd
boolean breakWhile = false; Sy*p6DP
wYS r.T8Q
>G[:Q s
while(!bStop) FKf2Q&2I
{ Kj?hcGl[
write_nPos(); u Vv%k5
Utility.sleep(500); WkpHe
breakWhile = true; %l%2 hvGZ
931GJA~g
i}|jHlv
for(int i=0;i<nStartPos.length;i++) J-klpr#
{ AS4oz:B
if(!fileSplitterFetch.bDownOver) (A?w|/bZd
{ 3:OqD~,zy
breakWhile = false; 9RK.+2
break; _3g!_
} $RC)e7
} -" r4
if(breakWhile) AOqL&z
break; .F _u/"**
mgq4g
79jnYjk
//count++; %bG\
//if(count>4) 02:`Joy2D
// siteStop(); ;c@B+RquR
} !b$~Sm)
`lbRy($L
:"i2`y;u
System.err.println("文件下载结束！"); :[C|3KKe"
} mZnsr@KF
catch(Exception e){e.printStackTrace ();} u@Z6)r'
} /p}pdXS
J'I1NeK
-2C^M> HZ
//获得文件长度 'OU3-K
public long getFileSize() e?GzvM'2
{ !bX
int nFileLength = -1; @c>MROlrlF
try{ {uqP+Cs
URL url = new URL(siteInfoBean.getSSiteURL()); *m'&<pg]X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w`/~y
httpConnection.setRequestProperty("User-Agent","NetFox"); Uw)B(;Hy?
9`&sZ|"3
'+GYw$
int responseCode=httpConnection.getResponseCode(); m&MZn2u[4i
if(responseCode>=400) $9G".T
{ k~QmDq
processErrorCode(responseCode); ZpwFC7LW
return -2; //-2 represent access is error Ubwmn!~
} ')WS :\J
Yic4|N?u
_Qb].~
String sHeader; \MAv's4b@
4Le{|B
)~w bu2;
for(int i=1;;i++) vhU#<59a1
{ tCj\U+;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); l5enlYH
//Utility.log(in.readLine()); D3+<16[,
sHeader=httpConnection.getHeaderFieldKey(i); [|C
if(sHeader!=null) JUq7R%"h6
{ 7e)j|a-!<
if(sHeader.equals("Content-Length")) FaaxfcIfkw
{ \`*]}48Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4Ub7T=LG
break; 0/~{,
} 'SWK{t \4
} $WQm"WAKe
else $o ;48uV^
break; GCxmqoQ
} E8aD[j[w
} 1<0Z@D~F
catch(IOException e){e.printStackTrace ();} >ATccv
catch(Exception e){e.printStackTrace ();} IL%P\Zs
YgQb(umK
7lzmAih
Utility.log(nFileLength); Jg6@)<n
-_>E8PhM
|tFg9RT
return nFileLength; :M@#.
} }~v0o# I
Se!B,'C%
#0Z%4WQ
//保存下载信息（文件指针位置） =o[H2o y
private void write_nPos() [3v&j_
{ -Y>QKS
try{ yM?jiy
output = new DataOutputStream(new FileOutputStream(tmpFile)); .ITTYQHv)
output.writeInt(nStartPos.length); NLev(B:OQH
for(int i=0;i<nStartPos.length;i++) o"qG'\x
{ 07vzVsQ}p
// output.writeLong(nPos); W: 3fLXk+
output.writeLong(fileSplitterFetch.nStartPos); af=lzKt*
output.writeLong(fileSplitterFetch.nEndPos); DV!0zzJ
} Fw%S%*B8g
output.close(); 3nx*M=
} a.XMeB
catch(IOException e){e.printStackTrace ();} }Gd^r
catch(Exception e){e.printStackTrace ();} 2bOFH6g
} wqJ1^>TB
LUA<N:
9#\oGzDN
//读取保存的下载信息（文件指针位置） q)RTy|NJ^
private void read_nPos() z+j3j2
{ )yS S2
try{ lh;;%@1DM
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Shu=oweJ
int nCount = input.readInt(); q=26($
nStartPos = new long[nCount]; TcH7!fUj
nEndPos = new long[nCount]; lkQ(?7
for(int i=0;i<nStartPos.length;i++) W'5c%SI
{ (_Rl f$D
nStartPos = input.readLong(); H `_{n<
nEndPos = input.readLong(); gV-A+;u
} Ots]y
input.close(); W"5VqN6v
} 9Hs5uBe
catch(IOException e){e.printStackTrace ();} ^7Z.~A y
catch(Exception e){e.printStackTrace ();} 0G8zFe*p
} vk3C&!M<a
K^c%$n:}+
35~1$uRA
private void processErrorCode(int nErrorCode) Q'Y7PG9m~
{ "lKR~Qi
System.err.println("Error Code : " + nErrorCode); P?<G:]W
} =gO4B-[
<p#+('N`
k}e~xbh-y
//停止文件下载 ;_A?Zl}
public void siteStop() !4T7@V`G
{ {br6*
bStop = true; ?rQIUP{D7
for(int i=0;i<nStartPos.length;i++) P:m6:F@hO
fileSplitterFetch.splitterStop(); +\25ynM
p u[S
~lr,}K,
} +{s -Fg
} 2h`Tn{&1/
//负责部分文件的抓取 g<YN#
**FileSplitterFetch.java 4X$|jGQ\
*/ e0`5PVJ
package NetFox; LDj*~\vsq
nRheByYm
70N Lv
import java.io.*; ?GeMD /]
import java.net.*; 0W]vK$\F*
+sx$%N
yjIA`5^
public class FileSplitterFetch extends Thread { QJU\YH%}
v}Kj+9h
%G'P!xQhy
String sURL; //File URL M[7$F&&n
long nStartPos; //File Snippet Start Position =8Gpov1!V~
long nEndPos; //File Snippet End Position HEe_K!_
int nThreadID; //Thread's ID Eb9n6Fg
boolean bDownOver = false; //Downing is over 0uJ??4N9
boolean bStop = false; //Stop identical 3NN)ql
FileAccessI fileAccessI = null; //File Access interface D[3QQT7c
>yqFO
vg*~t3{L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \ 9#X]H
{ ?~tx@k$;Es
this.sURL = sURL; X1^Q1?0
this.nStartPos = nStart; OF O,5
this.nEndPos = nEnd; y`8jz,&.
nThreadID = id; 'oF('uR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5GDg_9Bz
} Wn Ng3'6
{Hzj(c~S?
pLtK:Z
public void run() & DhdB0Hjf
{ |F&02f!]@
while(nStartPos < nEndPos && !bStop) ) RNB;K~s9
{ $ <Mf#.8%
lec3rv0)
@oQ"FLF.
try{ '8;'V%[+
URL url = new URL(sURL); a( SJ5t?-2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \hg%J/
httpConnection.setRequestProperty("User-Agent","NetFox"); kQO-V4z!
String sProperty = "bytes="+nStartPos+"-"; c uHF^l
httpConnection.setRequestProperty("RANGE",sProperty); d^d+8R
Utility.log(sProperty); TVAa/_y2`
nRs:^Q~o
6bT>x5?
InputStream input = httpConnection.getInputStream(); UHBMl>~z
//logResponseHead(httpConnection); =-/sB>-C
k\\e`=
0e(4+:0
byte[] b = new byte[1024]; 3(_:"?xA
int nRead; Uz%2{HB@{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )a<MW66
{ mnFmShu
nStartPos += fileAccessI.write(b,0,nRead); +QeA*L$~
//if(nThreadID == 1) D&G^|: G
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L+8O 4K{
} \w)ddc!ZS
7MQxW<0
o,{]<Sm
Utility.log("Thread " + nThreadID + " is over!"); -@.FnFa
bDownOver = true; &.P G2f*
//nPos = fileAccessI.write (b,0,nRead); P<=1OWC
} ,@\z{}~v
catch(Exception e){e.printStackTrace ();} C=JS]2W2
} DSlO.)dHu
} W=Mdh}u_I
oj@=Cq':-
gObafIA
//打印回应的头信息 Xq}}T%jcd
public void logResponseHead(HttpURLConnection con) ~/rKKc
{ S}qGf%
for(int i=1;;i++) G|TnvZ KX
{ dtig_s,)D
String header=con.getHeaderFieldKey(i); xXSfYW
if(header!=null) g @NwW&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _} K3}}
Utility.log(header+" : "+con.getHeaderField(header)); K$O2 Fq@y
else "bz]5c~
break; 4K*st8+bl-
} 1p=bpJC
} yw{r:fy
>X*Y jv:r
8+H 0
public void splitterStop() 1C0' Gf)3
{ 6W:FT Pt44
bStop = true; OxUc,%e9P
} 4'Ya-xx
rPt
pJuD+v
} Q{CRy-ha
).-#
`qRyh}Ax"
/* <'\!
**FileAccess.java M{SJ8+G
*//文件访问(定位，写) N6> rU
package NetFox; U>@AE
import java.io.*; 1DGl[k/zv
JP^\
8dCRSU
public class FileAccessI implements Serializable{ `?SC.KT
G ]uz$V6!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W }v ,6Oe
RandomAccessFile oSavedFile; xzOn[.Fi
long nPos; ]c bXI
/F6"uZSt4
[f}`reRlZ
public FileAccessI() throws IOException Fk9]u^j
{ 1 1(GCu
this("",0); 9e.$x%7j
} W8r"dK
<$d2m6J
vU(fd!V ?
public FileAccessI(String sName,long nPos) throws IOException m/,80J8L+f
{ cI/}rZ+
oSavedFile = new RandomAccessFile(sName,"rw"); 57O|e/2
this.nPos = nPos; $4qM\3x0,
oSavedFile.seek(nPos); *`LrvE@t
} V]m}xZ'?^
btC6R>0
&N]e pV>
public synchronized int write(byte[] b,int nStart,int nLen) H!Dj.]T
{ Q)lD2
int n = -1; sH'0utD#Y
try{ y&bZai8WlE
oSavedFile.write(b,nStart,nLen); 3to!C"~\K-
n = nLen; v#`>
} h:sf?X[
catch(IOException e) d1D=R8P_u
{ |o*qZ}6
e.printStackTrace (); 6q!Q([D_
} esq~Ehr=
[:qJ1^UU
Zg0nsNA
return n; f.bwA x
} (44L8)I.D
=#[t!-@
K9yZG
} p=#/H,2
j}`ku9S~
ecO$L<9>
/* ma!C:C9#J
**SiteInfoBean.java ]6s/y
*/ "]Uj _d
package NetFox; l*huKSX}
{u9n?Z%
4\k{E-x $
public class SiteInfoBean { D:?"Rf{)
(I(U23A~
Nl/ fvJ`4
private String sSiteURL; //Site's URL H8B2{]HAt
private String sFilePath; //Saved File's Path &4#%xg
private String sFileName; //Saved File's Name %tC[q
private int nSplitter; //Count of Splited Downloading File _[i.)8$7
{P\Ob0)q
q/Ji}NGm
public SiteInfoBean() 0>D*d'xLd
{//nSplitter的缺省值为5 'tcve2Tt
//default value of nSplitter is 5 9j5|o([J
this("","","",5); E:+r.r"Y
} 5wE6gRJ
#$L/pRC
z@?y(E
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0NU3% 4?
{ gg8)oc+w
sSiteURL= sURL; #3eI4KJ4+l
sFilePath = sPath; ^eefR5^_w
sFileName = sName; %cDDu$9;
this.nSplitter = nSpiltter; YC<FKWc
`ZO5-E
2PUB@B' +
} vpOGyvI
SG&H^V8
m=/HUt3(&0
public String getSSiteURL() AE`UnlUSF
{ $uUyp8F
return sSiteURL; 5|t-CY{?b
} ;`kOFg#`)c
&B=z*m
zV;NRf) 9.
public void setSSiteURL(String value) w)1SZ}
{ ZCb@!V}=
sSiteURL = value; b"`fS`@/MW
} /L2n ~/
DT6BFx
4ji'6JHPg
public String getSFilePath() 45iO2W uur
{ ,zH\P+*
return sFilePath; UfV {m
} l&"bm C:xr
<Hz11 }<(
M195[]
public void setSFilePath(String value) Qy=tkCN
{ ^h#A7 g
sFilePath = value; cXN0D\%`
} IM[=]j.?
6z/&j} (
K:Z,4Y
public String getSFileName() ;ByCtVm2
{ B>z^W+Unyn
return sFileName; 8^^ehaxy
} LW("/
RC8-6s& ln
d4Y[}Fcp+
public void setSFileName(String value) 3O2vY1Y2
{ 2(e;pM2Dq
sFileName = value; y^kC2DS
} {4p7r7n'
dr(e)eD(R>
YhAO
public int getNSplitter() KK-+vq
{ irjHPuhcG
return nSplitter; ?6I`$ &OA
} Aqg$q* Y
,p\*cHB9
7Bf4ojKt
public void setNSplitter(int nCount) qPhVc9D#
{ hKsx7`[
nSplitter = nCount; Esg:
} B8upv~U6
} gK dNgU
Vt9o8naz
Tilr%D(Q
/* <!|=_W6
**Utility.java gKIN* Od
*/ WFqOVI*l
package NetFox; ~n/:a
jd 8g0^
% %2~%FVb
public class Utility { d{C8}U
)*o) iN 7l
X<1ymb3
public Utility() ^4saB+qm
{ 9@*4^Ks p
Ac[;S!R
1;>RK
} BMhuM~?(
H"2,Q T
//线程睡眠 q93V'[)F
public static void sleep(int nSecond) mj y+_
{ gJzS,g1]
try{ F#efs6{
Thread.sleep(nSecond); er!+QD,EM
} OQT i$2
catch(Exception e) {Z[kvXf"mZ
{ VAa;XVmB
e.printStackTrace (); TR{dNO!q
} \z2d=E
} bW'Y8ok[v
IRI<no
//日志 '9|R7
public static void log(String sMsg) Zo,]Dx
{ q?&JS
System.err.println(sMsg); P$G|o|h
} j7HOh|q
+T7FG_
HYg7B
public static void log(int sMsg) ]m^ECA$
{ Lismo#
System.err.println(sMsg); It^_?oiK
} y? 65*lUl
} tLx8}@X"
'}NH$ KA
DAd$u1
/* m3_)UIJZ
**TestMethod.java u+8?'ZT,
*/ );x[1*e
package NetFox; k:zGv
XpOQBXbt
9M-/{D^+<
public class TestMethod { _]=, U.a=/
-QP1Se*#
OB~74}3;
public TestMethod() ~bJ*LM?wOP
{ ///xx/weblogic60b2_win.exe O<w7PS
try{ cK+)MFOu+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *|:]("i
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y]f| U-f:~
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4:v{\R
fileFetch.start(); C/pu]%n@4
} <8/lHQ^\)
catch(Exception e){e.printStackTrace ();} &,`P%a&k
aw/5#(1R
#Y<b'7yJ
} zX/9^+p:
KHXnB
\(ZOt.3!J
public static void main(String[] args) uM~j
{ ]qc2jut"
new TestMethod(); ZCVN+::Y
} cb~m==G
} \Tj(]
点击下载更多相关资料