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)); `|^<y.-6
} E4'D4@\W
for(int i=0;i<nEndPos.length-1;i++) '#.:%4
{ rS 4'@a
nEndPos = nStartPos[i+1]; ka&-tGg
} uXNf)?MpA
nEndPos[nEndPos.length-1] = nFileLength; VM3H&$d(h
} NOa.K)^k
} NB&u^8b
| We @p
'ga1SbA]
//启动子线程 IfZaK([
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +Hb6j02#
for(int i=0;i<nStartPos.length;i++) G\H@lFh
{ @$79$:q N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j1>77C3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^~5tntb.
nStartPos,nEndPos,i); NoJo-vo*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -7">A~c
fileSplitterFetch.start(); .6E7 R
} AMYoSc
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A_%}kt (6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gHlahg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,9#G/nF
nEndPos = " + nFileLength); k- sbZL
// fileSplitterFetch[nPos.length-1].start(); " I@Z:[=2
^U_B>0`ch
$XI5fa4Tt
//等待子线程结束 pKMf#)qm
//int count = 0; 7@vcQv kC
//是否结束while循环 *k'9 %'<
boolean breakWhile = false; j86s[Dty
I01On>"@7
)M]4p6Y
while(!bStop) BsB}noN}
{ U&Ay3/
write_nPos(); \+MR`\|3
Utility.sleep(500); aG\m3r
breakWhile = true; 0{PK]qp7
d<6L&8)<
_uHyE }d
for(int i=0;i<nStartPos.length;i++) kQIWDN
{ fINM$ 6
if(!fileSplitterFetch.bDownOver) cx2s|@u0
{ $Y,]D*|"K
breakWhile = false; $vy.BYFm
break; #OWwg`AWv
} ~ilbW|s?=k
} (p14{
if(breakWhile) `s:| 4;.
break; .(S,dG0P
/p>"|z
~N'KIP[W
//count++; 66'TdF]"
//if(count>4) h)wR[N]n
// siteStop(); ~:)$~g7>b
} :M3l#`4Q
O:7y-r0i
6g$04C3tHi
System.err.println("文件下载结束！"); u'K<-U8H
} >/bl r}5 H
catch(Exception e){e.printStackTrace ();} lGLZIp
} RFK N,oB
\\)-[4uC
/2HwK/RZ
//获得文件长度 S|]~,l2]}
public long getFileSize() Gs?W7}<$
{ 9$DVG/
int nFileLength = -1; %q*U[vv
try{ ?$n<vF>
URL url = new URL(siteInfoBean.getSSiteURL()); o3WkbMJWM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KUyua~tF
httpConnection.setRequestProperty("User-Agent","NetFox"); ~+lC%R
e-}PJ%!,T
aYj3a;EmU
int responseCode=httpConnection.getResponseCode(); //+UQgl6
if(responseCode>=400) (`!| Uf$
{ +&?VA!}.
processErrorCode(responseCode); iD(K*[;lc
return -2; //-2 represent access is error NOS5bm&-
} 7GP?;P
Ew:JpMR
_~cmR<
String sHeader; OC>" +
Jx>P%>+<j
<m(nZ'Zqz2
for(int i=1;;i++) r\3In-(AT
{ F}01ikXDb'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lHGv:TN
//Utility.log(in.readLine()); Xj-3C[8@
sHeader=httpConnection.getHeaderFieldKey(i); \:=Phbn
if(sHeader!=null) Sej$x)Q\t
{ 5;^8wh(
if(sHeader.equals("Content-Length")) 84knoC
{ .M! (|KE4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i5n'f6C
break; QHM39Eu]
} ./g0T{&
} kv5Qxj}
else ?APzx@$D.
break; ^2??]R&Q
} 1Xs!ew)>
} B\=&v8
catch(IOException e){e.printStackTrace ();} Z?x]HB`r
catch(Exception e){e.printStackTrace ();} 7]v-2 *
[MEa@D<7N
A!f0AEA,
Utility.log(nFileLength); Yr31GJ}K
0?:ZERv
T5Fah#-4
return nFileLength; w}1)am&pD
} Sph+kiy|
/d=$,q1
3|?fGT;P
//保存下载信息（文件指针位置） *m"mt
private void write_nPos() O:x=yj%^
{ 8zGzn%^
try{ 82=][9d #
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1Jd:%+T
output.writeInt(nStartPos.length); 08` @u4
for(int i=0;i<nStartPos.length;i++) @E)XT\;3
{ {l6]O
// output.writeLong(nPos); W[?B@sdSZ
output.writeLong(fileSplitterFetch.nStartPos); )5t_tPv
output.writeLong(fileSplitterFetch.nEndPos); Qpc{7#bp
} xl9l>k6,
output.close(); lxd<^R3i#^
} dg!sRm1iZ:
catch(IOException e){e.printStackTrace ();} UEeqk"t^
catch(Exception e){e.printStackTrace ();} uJO*aA{K
} /Yh([P>
f6"j-IW[z
us cR/d
//读取保存的下载信息（文件指针位置） E.6\(^g
private void read_nPos() ~9c9@!RA2
{ bk?\=4B:E
try{ y,x~S\>+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Gt%kok
int nCount = input.readInt(); 3edAI&a5
nStartPos = new long[nCount]; QCo^#-
nEndPos = new long[nCount]; gvJJ.IX]+
for(int i=0;i<nStartPos.length;i++) 6:!fyia
{ 9j"\Lr*o"
nStartPos = input.readLong(); S'O0'5U@
nEndPos = input.readLong(); Yru[{h8hw`
} + ND9###
input.close(); .3&m:P8zV
} ;H=6u
catch(IOException e){e.printStackTrace ();} 2ya`2 m
catch(Exception e){e.printStackTrace ();} *O5+?J Z!
} Q.\>+4]1&&
6)$_2G%Zq
[GuDMl3hC
private void processErrorCode(int nErrorCode) \f LBw0
{ }B-A*TI<h
System.err.println("Error Code : " + nErrorCode); Dpd$&Wr0Y
} UE4#j\
pUr[MnQLf
7" [;M
//停止文件下载 LZVO9e]
public void siteStop() x\DkS,O
{ ' 7A7HDJ
bStop = true; _#O?g=1
for(int i=0;i<nStartPos.length;i++) >+#[O"
fileSplitterFetch.splitterStop(); JW\"S
+Xp;T`,v
-AT@M1K7%
} zT% kx:Fk
} @\y7 9FX
//负责部分文件的抓取 P1QJ'eC;T
**FileSplitterFetch.java Kq$Zyf=E
*/ ie!4z34
package NetFox; W!k6qTz)
3EvA 5K.
#+;=ijyF
import java.io.*; taQ[>x7b
import java.net.*; T_uuFL
O5Lv:qAa
;]Aa
public class FileSplitterFetch extends Thread { >D<=9G(a
;$QJnQ"R
a{+oN $
String sURL; //File URL DR /)hAE
long nStartPos; //File Snippet Start Position mTfMuPPs[
long nEndPos; //File Snippet End Position uFm-HR@4
int nThreadID; //Thread's ID "{_"NjH
boolean bDownOver = false; //Downing is over ^H4iHjg
boolean bStop = false; //Stop identical deoM~r9s
FileAccessI fileAccessI = null; //File Access interface .y/b$|d,
$D5U#
h+UscdUl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :RsPGj6
{ cPcV[6)5K9
this.sURL = sURL; C=IH#E=
this.nStartPos = nStart; ?C:fP`j:
this.nEndPos = nEnd; kA4ei
nThreadID = id; ".%LBs~$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;ZJ,l)BNO
} PHvjsA%"
/09=Tyy/\
\6hL W_q1
public void run() `5Btg. &
{ hD1AK+y
while(nStartPos < nEndPos && !bStop) Wts{tb
{ `4bd,
(J&Xo.<Z-
mM*yv
try{ lrhAO"/1
URL url = new URL(sURL); k+[KD>;1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +ca296^
httpConnection.setRequestProperty("User-Agent","NetFox"); Nr9[Vz?$P
String sProperty = "bytes="+nStartPos+"-"; gKN_~{{OD
httpConnection.setRequestProperty("RANGE",sProperty); b3xkJ&Z
Utility.log(sProperty); j/D)UWkR
\`&pk-uW
P(epG?Qg
InputStream input = httpConnection.getInputStream(); _}@n_E
//logResponseHead(httpConnection); ?(q*U!=
Vb^s 'k
4i/q^;`
byte[] b = new byte[1024]; 0>=)
int nRead; #2jn4>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *\KMkx
{ Hi_Al,j:
nStartPos += fileAccessI.write(b,0,nRead); RYl3txw
//if(nThreadID == 1) _[i=TqVmf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !rg0U<bO!
} @>2rz
V6MT>T
93IOG{OAY
Utility.log("Thread " + nThreadID + " is over!"); 4AOS}@~W
bDownOver = true; M/a/H=J
//nPos = fileAccessI.write (b,0,nRead); C;q}3c*L
} _(`X .D
catch(Exception e){e.printStackTrace ();} mN{ajf)@
} B"m:<@ "
} Kxc$wN<
O2]r]9sh*
=6<w'>
//打印回应的头信息 ;b?+:L
public void logResponseHead(HttpURLConnection con) 1qj%a%R
{ >zg8xA1zL
for(int i=1;;i++) v*~%x
{ J(0=~Z[
String header=con.getHeaderFieldKey(i); {]\uR-a(o
if(header!=null) 3Ge<G
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AKKU-5 B9c
Utility.log(header+" : "+con.getHeaderField(header)); C.eV|rc@T
else cm@oun
break; 1LE^dS^V
} e4qk>Cw
} ~5 pC$SC6>
#/t>}lc
92aDHECo
public void splitterStop() 4 uy@ {
{ 9Ir~X|}\iL
bStop = true; y-<PsP-I
} B:- KZuO
|369@un6
O\?5#.
} vQYfoam;
_`@Xy!Ye
+z(,A
/* m0A@jWgd
**FileAccess.java B#GZmv1
*//文件访问(定位，写) !qXq y}?w
package NetFox; GQ-e$D@SfB
import java.io.*; 0|s$vqc
udEb/7ZL
Gj7QGIKx
public class FileAccessI implements Serializable{ oyN+pFVB:$
ccN&h
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /cL9?k;o
RandomAccessFile oSavedFile; FJjF*2.
long nPos; I6hhU;)C
TtwJ,&b
Z|:_c
public FileAccessI() throws IOException =o{: -EKQF
{ 0(9I\j5`TT
this("",0); ~e`;"n@4
} {7TJgS
>b4YbLkI#
+<!)k?
public FileAccessI(String sName,long nPos) throws IOException "`jZ(+
{ 1!;"bHpk
oSavedFile = new RandomAccessFile(sName,"rw"); s;_#7x#
this.nPos = nPos; G{:af:5Fo
oSavedFile.seek(nPos); UOLTCp?M;J
} S0.- >"L
1RI#kti-"
/md Q(Dm
public synchronized int write(byte[] b,int nStart,int nLen) 9Nag%o{*S>
{ o^_W$4Fc
int n = -1; L^5&GcHP0
try{ @}&,W N%
oSavedFile.write(b,nStart,nLen); uD ?I>7
n = nLen; p9&gEW
} 3)C6OF>7
catch(IOException e) nz&b5Xb2
{ dEQReD
e.printStackTrace (); |%:qhs,
} )~?S0]j}
[al(>Wr9
0i`v:Lq%
return n; Y uw E 0
} 2pxWv )0
rY[3_NG%
hpqHllL
} ,NaV ["9$
n~"g'Y
EbBv}9g
/* xS H6n
**SiteInfoBean.java ,<Grd5em.
*/ PUQ_w
package NetFox; =#.8$oa^
%)<oX9E
OUlxeo/
public class SiteInfoBean { I*+LJy;j
)I Y 5Y
XDP6T"h
private String sSiteURL; //Site's URL r|\5'ZMx
private String sFilePath; //Saved File's Path %67G]?EXB
private String sFileName; //Saved File's Name /^z/]!JG:V
private int nSplitter; //Count of Splited Downloading File LM"W)S
'FPcAW^8
45r]wT(C
public SiteInfoBean() vu_>U({. T
{//nSplitter的缺省值为5 =A0"0D{\
//default value of nSplitter is 5 @sB}q 6>
this("","","",5); Qb6QXjN Q
} u n?j
wL8bs- U
F1?CqN M
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ks49$w<
{ d$"G1u~%
sSiteURL= sURL; jpYw#]Q
sFilePath = sPath; fH#F"^A
sFileName = sName; g)Vq5en*
this.nSplitter = nSpiltter; "%.|n|
=RW* %8C
<t?x 'r?@
} w2uRN?
AND7jEn
m{:"1]
public String getSSiteURL() dT0^-XSY
{ o ;[C(OS
return sSiteURL; YiIddQ
} sW]yuu!/
vF.?] u
Vr&el
public void setSSiteURL(String value) RR[)UQ
{ i$`|Y*
sSiteURL = value; P;)2*:--)
} >~`Y
_SMT.lG
S F&M (=w<
public String getSFilePath() p<of<YU)
{ ESC
return sFilePath; ql{^"8x
} =R8f)UQYx
(ZE%tbm2
CbTf"pl
public void setSFilePath(String value) Qag|nLoT
{ "jl1.Ah
sFilePath = value; {&\J)oZ
} @K,2mhE~h
pTa'.m
\b_-mnN"
public String getSFileName() im_w+h%^
{ ^Ei*M0fF
return sFileName; ~I8v5 H
} +?URVp
MAuM)8_P/|
ppwd-^f3j
public void setSFileName(String value) w$DG=!
{ cOzg/~\1
sFileName = value; &_Cxv8
} bajC-5R1k
3gxf~$)?
Ep^B,;~
public int getNSplitter() lSZ"y Q+
{ (/T+Wpy?
return nSplitter; c+szU}(f6(
} RtW4n:c
|RHO+J
$se !8s"
public void setNSplitter(int nCount) S 3{Dn
{ DWF >b
nSplitter = nCount; '4J&Gpx
} 21.YO]Et
} (P2[5d|
P/FrE~
Zr\2BOcc.l
/* pO\S#GnX
**Utility.java ! a86iHU
*/ n (OjjRm
package NetFox; jFgZ}Xp
4qqF v?O[r
slu$2-H
public class Utility { 0w^jls
$`^H:Djr
F?!FD>L{`
public Utility() l>A\V)
{ ri_P;#lz
|c<XSX?ir
jjxIS
} Sq?,C&LsA
RwUW;hU
//线程睡眠 |__d 8a
public static void sleep(int nSecond) G?>qd}]y0L
{ ozVpfs
try{ uRP Ff77
Thread.sleep(nSecond); P~&O4['<
} ;9K[~
catch(Exception e) rZ pbu>S
{ /#29Y^Z)=
e.printStackTrace (); STv(kQs
} F/)f,sZF
} g .3f2w
1U
//日志 RTA%hCr!
public static void log(String sMsg) VZ;@S3TS
{ *8/VSs
System.err.println(sMsg); v<j2L"bj
} d"Bo8`_
:#qUMiu$
Tu==49
public static void log(int sMsg) X!o@f$
{ fTTm$,f5N
System.err.println(sMsg); u]R$]&<
} T{ok +$w2
} av$
Q^nG0<q+
[@g~
/* " l.!Ed
**TestMethod.java f7.m=lbe
*/ P7'M],!9w
package NetFox; '\@WN]
hUBF/4s\
_'&k#Q
public class TestMethod { 2,+d|1(4o
70{RDj6{
@#A!w;bz
public TestMethod() T=.-Cl1A
{ ///xx/weblogic60b2_win.exe QJQJR/g
try{ D_Guc8*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jBS'g{y-!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j+nv=p
SiteFileFetch fileFetch = new SiteFileFetch(bean); (p^S~Ax
fileFetch.start(); FbmsN)mv!%
} u9BjgK(M
catch(Exception e){e.printStackTrace ();} f0OgK<.>T
'w:bs!
KLW&bJ$|j
} S3QaYq"v
1}`2\3,
rJX\6{V!_
public static void main(String[] args) !F-sA: xq
{ _;#9!"&
new TestMethod(); 2av*o~|J*:
} Zct!/u9 Q
} z1#oWf{*
点击下载更多相关资料