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)); c@q>5fR/c
} l2`8]Qr
for(int i=0;i<nEndPos.length-1;i++) T)Nis~
{ >v<}$v6D~
nEndPos = nStartPos[i+1]; ,.}PZL
} uV 6f~cQ
nEndPos[nEndPos.length-1] = nFileLength; G(0bulq
} j^!J:Bj
} kkOYC?zE?
Mc6Cte]3|
nC&rQQFF
//启动子线程 @xkM|N?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _mkI;<d]$T
for(int i=0;i<nStartPos.length;i++) 63u'-Z"4
{ )sS<%Xf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @e0Q+t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $0W0+A$
nStartPos,nEndPos,i); 'b^:"\t'Rh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t=e0z^2i+
fileSplitterFetch.start(); 2iG(v._x
} D@JHi'F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -owfuS?i=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #i]@"R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }> 1h+O
nEndPos = " + nFileLength); ~IWi@m{
// fileSplitterFetch[nPos.length-1].start(); 4rzioIk
462ae` 6l
*r%mqAx(
//等待子线程结束 <s7{6n')
//int count = 0; g<dCUIbcQ
//是否结束while循环 ~!nd'{{9
boolean breakWhile = false; #U_u~7?H$
pM7BdMp
PvB?57wkF
while(!bStop) fVN}7PH7+
{ i ('EBO
write_nPos(); =4%C?(\
Utility.sleep(500); yED^/=\)}
breakWhile = true; AeJM[fCMa
f%}+.eD
jN<]yhqf
for(int i=0;i<nStartPos.length;i++) QNtr=
{ bn(Scl#@K
if(!fileSplitterFetch.bDownOver) 0Its;|
{ Q:MsD.
breakWhile = false; q7PRJX
break; Z{CL!
} jI V? p
} /&|pXBY$;
if(breakWhile) Yptsq@s
break; LK%B6-;~-
=Ffq =<
G_<[sMC8
//count++; ~^C7(g )
//if(count>4) g`6wj|@ =W
// siteStop(); <Ztda !
} eJA{]^Zf
.5ycO
*h%G4M
System.err.println("文件下载结束！"); KN`z68c4L
} Q+Fw =Xw
catch(Exception e){e.printStackTrace ();} ppD~xg]
} A X#!9-m3
U`Ag|R
A-u5
//获得文件长度 =iQm_g
public long getFileSize() 0EB'!
{ Rp|&1nS
int nFileLength = -1; U;xWW9
try{ @iceMD.
URL url = new URL(siteInfoBean.getSSiteURL()); 3d<HIG^W}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H44&u](8{
httpConnection.setRequestProperty("User-Agent","NetFox"); |G@)B!>
3,5wWT] )
N9PM.nbd%
int responseCode=httpConnection.getResponseCode(); [-gKkOT8E
if(responseCode>=400) <khAc1"
{ UmE{>5Pt
processErrorCode(responseCode); \|t0~sRwh
return -2; //-2 represent access is error y~=hM
} i+Dgw
csM|VNE>
S}f<@-16P
String sHeader; )89jP088V
rQm
8'[wa
for(int i=1;;i++) -8jqC6mQ
{ \@3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &NQR*Tn
//Utility.log(in.readLine()); eM"mP&TTL
sHeader=httpConnection.getHeaderFieldKey(i); sN}@b8o@
if(sHeader!=null) t>sX.=\$
{ kw~H%-,]
if(sHeader.equals("Content-Length")) $Ig,cTR.b
{ S:uEK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SkA'+(
break; XXcf!~uO
} .8!0biS
} FxX3Pq8h
else `VE&Obp[
break; P$ef,ZW"
} o)=VPUe
} EI.Pk>ZIm
catch(IOException e){e.printStackTrace ();} =*}Mymhk(
catch(Exception e){e.printStackTrace ();} +|<&#b0Xd
aF"Z!HD
Hc%\9{zH
Utility.log(nFileLength); =M#?*e
-b}S3<15@
X4G55]D$>
return nFileLength; %Nl(Y@dD*
} @e0skc
[s{:}ZuKc
Ur(o&,
//保存下载信息（文件指针位置） .6F3;bg R7
private void write_nPos() I?g__u=n~
{ @qy*R'+
try{ b[;3KmUB
output = new DataOutputStream(new FileOutputStream(tmpFile)); 'aP*++^
output.writeInt(nStartPos.length); I<K/d
for(int i=0;i<nStartPos.length;i++) ==Mi1Q#5C
{ 5 hadA>d
// output.writeLong(nPos); Hk*cO;c
output.writeLong(fileSplitterFetch.nStartPos); }n%Rl\p
output.writeLong(fileSplitterFetch.nEndPos); m Ap|?n/K
} n{r#K_
output.close(); $ ].k6,%{p
} G)Bq?=P
catch(IOException e){e.printStackTrace ();} 6CmFmc,
catch(Exception e){e.printStackTrace ();} # pB:LPEsK
} =DTOI
e=UVsYNx
cloSJmUlQ
//读取保存的下载信息（文件指针位置） F'$S!K58
private void read_nPos() $jh>zf
{ )9*3^v
try{ gNN" H#=2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); sg"D;b:X
int nCount = input.readInt(); Z"|P(]A
nStartPos = new long[nCount]; xM//]
nEndPos = new long[nCount]; ]N"F?3J 8
for(int i=0;i<nStartPos.length;i++) X7d.Ie
{ fP1OH&Ar
nStartPos = input.readLong(); sVdK^|j
nEndPos = input.readLong(); ('6g)@=\U
} &qP-x98E?
input.close(); tZ j,A%<
} :U.)YHY
catch(IOException e){e.printStackTrace ();} rL sK-qQ
catch(Exception e){e.printStackTrace ();} u<shhb-
} 8{Eo8L'V
n=o'ocdS)
tm1UH 4
private void processErrorCode(int nErrorCode) 6Hbf9,vI
{ `h9)`*
System.err.println("Error Code : " + nErrorCode); V<V\0n!0
} .!8X]trEg
i;hc]fYb=K
niHL/\7u
//停止文件下载 <uKm%~xi<
public void siteStop() s P4,S(+e
{ jc.JX_/
bStop = true; zMYd|2bc
for(int i=0;i<nStartPos.length;i++) "I}Z2
fileSplitterFetch.splitterStop(); l5Wa'~0qA
?5v5:U(A
{I-a;XBX
} k gu[!hD1
} 7Jx-W|
//负责部分文件的抓取 C{hcK 1-K
**FileSplitterFetch.java M1^C8cz
*/ soq".+Q
package NetFox; %L13Jsw
l \^nC2
<VaMUm<2
import java.io.*; %|(?!w7
import java.net.*; C9F+e
N.{jM[\F
VHT@s7u0"
public class FileSplitterFetch extends Thread { /uE^H%9h
[)SR$/A
^[,s_34V
String sURL; //File URL ~x4B/zW?
long nStartPos; //File Snippet Start Position oCKM5AVWsv
long nEndPos; //File Snippet End Position Hg9.<|+yo
int nThreadID; //Thread's ID _0W;)v
boolean bDownOver = false; //Downing is over i,IM?+4
boolean bStop = false; //Stop identical KHlIK`r
FileAccessI fileAccessI = null; //File Access interface 3U~lI&
J/x@$'
+:,`sdv6o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rFq@]t3q
{ N8XC~Dh{
this.sURL = sURL; J,1osG<6x
this.nStartPos = nStart; },fo+vRM
this.nEndPos = nEnd; u.kYp
nThreadID = id; G?ugMl}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JOdwv4(3V
} U$A7EFK'
Q-`{PJ(p
D!RE-w92X
public void run() (}C^_q:7d
{ $,;S\JmWP
while(nStartPos < nEndPos && !bStop) kWs+2j
{ Aa`MK$29F
T")i+v
pYfV~Q^3
try{ IypWVr
URL url = new URL(sURL); Vj=Xcn#*8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3@yTzaq6
httpConnection.setRequestProperty("User-Agent","NetFox"); W ~Jzqp9g
String sProperty = "bytes="+nStartPos+"-"; i$bzdc#s
httpConnection.setRequestProperty("RANGE",sProperty); XD^dlL
Utility.log(sProperty); _;e!ZZLG
fQQsb 5=i
"X5_-l
InputStream input = httpConnection.getInputStream(); 6)wy^a|pb
//logResponseHead(httpConnection); i-k >U}[%
|}M0,AS
If-,c^i
byte[] b = new byte[1024]; ~ThVap[*
int nRead; p?V?nCv1O
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) oSn! "<x
{ ';b3Mm #
nStartPos += fileAccessI.write(b,0,nRead); (LRM~5KVg
//if(nThreadID == 1) |.(CIu~b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4bi NGl~
} zj>aaY
h`5YA89
J%\- 1
Utility.log("Thread " + nThreadID + " is over!"); AfRW=&xdT
bDownOver = true; X&(<G
//nPos = fileAccessI.write (b,0,nRead); *K(k Kph
} +}^|dkc
catch(Exception e){e.printStackTrace ();} W|25t)cJ8h
} ^sifEgG*d
} Qz@IK:B}
oTCzYY
`/O`OrZ1K
//打印回应的头信息 Tm)GC_
public void logResponseHead(HttpURLConnection con) BTTLy^
{ u^Nxvx3l0
for(int i=1;;i++) <vB<`
{ }bf=Ntk
String header=con.getHeaderFieldKey(i); (#!]fF"!x
if(header!=null) |5xYT 'V
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eOm< !H
Utility.log(header+" : "+con.getHeaderField(header)); <nWKR,
else 0n:?sFY>
break; ?;|@T ty%
} b!0DH[XKV
} /gz:zThf{
#?{qlgv<p
YijMF/Uyb
public void splitterStop() S&4+ e:K
{ /!3ZWXY\
bStop = true; D|d4:;7
} 7\A4vUI3
*Jvxs R'a1
FR x6c
} E *F*nd]K
9>by~4An?
A4G,}r *n
/* (CdJ;-@D
**FileAccess.java VF)uu[ f9
*//文件访问(定位，写) \q~w<%9Dq
package NetFox; -2F@~m|
import java.io.*; hv*>%p
mxQR4"]jY
Q}kfM^i
public class FileAccessI implements Serializable{ bfgz1 `u
ao#!7F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M[, D *
RandomAccessFile oSavedFile; 4% HGMr
long nPos; AL$W+')
o=pt_!i/
RMoJz6^>
public FileAccessI() throws IOException w |_GV}#_
{ 2fJ{LC
this("",0); v:KX9A.
} *5'.!g('
[oV{83f
bpCNho$
public FileAccessI(String sName,long nPos) throws IOException #(C/Cx54
{ >':5?\C+-
oSavedFile = new RandomAccessFile(sName,"rw"); b1u}fp GF
this.nPos = nPos; ! ja[4.
oSavedFile.seek(nPos); LP:nba:
} $5,~JYcb
!tEe\K\e
9)+@0fG)
public synchronized int write(byte[] b,int nStart,int nLen) -G9|n#zCU
{ G.g|jP'n
int n = -1; ?GdsOg^
try{ _\.{6""
oSavedFile.write(b,nStart,nLen); k#O,j pbB
n = nLen; mwh{"FL(
} oid[syPB
catch(IOException e) $;2)s}ci
{ o(*F])d;
e.printStackTrace (); bd!U)b(}OV
} Cq>6rn
< f(?T`
z{:-!oF&CB
return n; @6 /yu>%
} yGTziv!
xjo;kx\y^
|uI?ySF
} =m7H)z)i*J
fW?sYC'
["y6b*;x
/* 9#7J:PfZ<
**SiteInfoBean.java ,_jC$
*/ @x1%)1
package NetFox; !Xj#@e
qI%&ay"/
V1B(|P
public class SiteInfoBean { hQRL,?
vE%s,E,
~6`iY@)
private String sSiteURL; //Site's URL *5k+t
private String sFilePath; //Saved File's Path w{!(r
private String sFileName; //Saved File's Name ExVDkt0
private int nSplitter; //Count of Splited Downloading File tx"LeZZ
x)SralWb
3J~0O2
public SiteInfoBean() W@.Ji B
{//nSplitter的缺省值为5 j8++R&1f]
//default value of nSplitter is 5 f'X9HU{Cz
this("","","",5); g # S0V
} ^s&W>hTX:
u%3i0BajY
5\bJR0I@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +m)q%I>
{ &]F3#^!^
sSiteURL= sURL; @MiH(.Dq
sFilePath = sPath; }4&/VvN
sFileName = sName; P(,?#+]-
this.nSplitter = nSpiltter; qnChM;)
`zA#z />
VT\"q1)p
} X|}2_B
j.m(ltGh
#Exp51
public String getSSiteURL() ;),"M{"v
{ Es!Q8.
return sSiteURL; kGHQ`h
} F]EBD8/b
;AX8aw,
j+rG7z){K
public void setSSiteURL(String value) wM~H(=s`D
{ wi_'iv
sSiteURL = value; SmhGZ
} I9?Ec6a_
\]uV!)V5B
V`kMCE;?l
public String getSFilePath() NI aFI(
{ ;=4Xz\2
return sFilePath; *bd[S0l
} $,3J7l3
u JY)4T
=>iA gp'#
public void setSFilePath(String value) TP%+.#Fu
{ .fAv*pUzU
sFilePath = value; M}O}:1Par
} wSEWwU[
0hY{<^"Y
v6GPS1:a
public String getSFileName() i#/]KsSp
{ !| #83
return sFileName; Jrxz'9qRG
} &@% $2O.3
Qm4o7x{q
A1"SLFY
public void setSFileName(String value) x79Ha,
{ C0jj(ku&
sFileName = value; }}&#|)Yq
} ^uBxgWIC
? *>]")[>
bq>_qpr
public int getNSplitter() ?t](a:IX
{ gw36Ec<M
return nSplitter; >w+HHs/$wK
} wE]K~y!`
q1?&Ev^
s{0aBeq
public void setNSplitter(int nCount) 8NBT|N~N
{ nUS| sh
nSplitter = nCount; !3X0FNGq
} D^Jk@<*
} [F!Y%Zp
U;N:j8
H@bf'guA|B
/* `h:34RC;
**Utility.java U*3J+Y
*/ LbEM^D
package NetFox; f| _u7"OX
/!h;c$
Rk!X]-`=
public class Utility { R;,g1m|]
1#IlWEg
1W7%1FA
public Utility() H0m|1 7
{ Od f[*
1 zw*/dp
wE+${B03
} p sL?Y
<sK4#!K
//线程睡眠 OC-gA}FZ-}
public static void sleep(int nSecond) [8tL"G6s
{ _SW3_8SuM.
try{ !*RqCS,
Thread.sleep(nSecond); dXF^(y]l
} ,) J~,^f6
catch(Exception e) 93Co}@Y;Y+
{ lpz2 m\
e.printStackTrace (); Z#rB}
} th;{V%:LW
} +$g}4
9eH$XYy
//日志 ` ,SiA-3*
public static void log(String sMsg) v`M3eh@$A
{ d_IAs
System.err.println(sMsg); w.[ "p9tc
} oYukLr
:j+ ZI3@
:Nz9xD$S5
public static void log(int sMsg) \B,(k<
{ ZIQ [bE7
System.err.println(sMsg); D8$G`~hD
} =weSyZ1~
} )ubiB^g'm
R6]Gk)5
EM[WK+9>I{
/* /pT=0=
**TestMethod.java m6w].-D8
*/ RS8Hf~0G
package NetFox; zzX_q(:S
PpAu!2lt9
y!_C/!d
public class TestMethod { !6*"(
?.Ca|H<
c9&xe"v
public TestMethod() Sy0$z39
{ ///xx/weblogic60b2_win.exe ]GW]dM
try{ Zcx`SC-0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )8$=C#qC[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tM'P m
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9-fLz?J
fileFetch.start(); ,Ge"anO
} Qo{/@
catch(Exception e){e.printStackTrace ();} RO'7\xvn
Na]:_K5Dp
k@k&}N0{
} Z/Dx,zIR
<^5Z:n!q
4\8+9b\9"
public static void main(String[] args) jK& h~)
{ rrik,qyv6
new TestMethod(); B#Vz#y
} e#$]Y?,
} Lr~=^{
点击下载更多相关资料