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)); p}(pIoyUF
} VJOB+CKE
for(int i=0;i<nEndPos.length-1;i++) uQO\vRh0
{ [,Fu2j]
nEndPos = nStartPos[i+1]; *:8,w?Nt
} iPdR;O'
nEndPos[nEndPos.length-1] = nFileLength; wrAcVR
} yyc4'j+
} `{ ` W-C
`[F[0fY-
Wh^wKF~%
//启动子线程 L-VisZ-FK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m e2$ R>@
for(int i=0;i<nStartPos.length;i++) &Rt^G
{ .RN2os{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O>[B"mMt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KZ$^Q<d^
nStartPos,nEndPos,i); k@^T<Ci
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e7M6|6nb
fileSplitterFetch.start(); ,Y`TP4Ip
} _`+2e-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), npMPjknl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a3C\?5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $aDkZj
nEndPos = " + nFileLength); z@U5
// fileSplitterFetch[nPos.length-1].start(); {C5-M!D{<
I\Pw`
/TY=ig1z
//等待子线程结束 q*7:L
//int count = 0; 1)J' pDa
//是否结束while循环 ,$bK)|pGV
boolean breakWhile = false; Y3bZ&G)
U?A3>
%,f(jQfg_
while(!bStop) mO&zE;/[
{ `2,F!kCt
write_nPos(); Vw+RRi(
Utility.sleep(500); @o>3 Bv.
breakWhile = true; ?6//'bO:%
?<U">8cP
xP$\ }
for(int i=0;i<nStartPos.length;i++) $Go)Zs-bL?
{ QSyPtjg]
if(!fileSplitterFetch.bDownOver) V=)' CCi{
{ FQM9>l@6)>
breakWhile = false; {QVs[ J1
break; =i>i,>bv
} wVkRrFJ
} VF:95F;@
if(breakWhile) zR5KC!xc
break; l09DH+
I8VCR8q
A$-\Er+f
//count++; r>g5_"FL
//if(count>4) .~fov8
// siteStop(); KN".0WU
} *{dMo,.eI
LN`Y`G|op
<\oD4EE_
System.err.println("文件下载结束！"); }s:~E2?In
} @.} @K
catch(Exception e){e.printStackTrace ();} fT.MglJcb
} Zw_'u=r >
naVbcY
6rMNp"!
//获得文件长度 |jb,sd[=S
public long getFileSize() 0}N"L ml
{ @|<qTci
int nFileLength = -1; C sCH :>
try{ :H>0/^Mg0
URL url = new URL(siteInfoBean.getSSiteURL()); /]-a 1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }70A>JBw
httpConnection.setRequestProperty("User-Agent","NetFox"); #3_ @aq*
~8U0(n:^
>tE6^7B*
int responseCode=httpConnection.getResponseCode(); LvNulMEK
if(responseCode>=400) C/MQY:X4
{ Fb6d1I^wR
processErrorCode(responseCode); X<&Y5\%F
return -2; //-2 represent access is error d fSj= 4
} #@J{ )
MzE1he1
QypUBf
String sHeader; p{AX"|QM"
A=r8_.@2@
wY3|5kbDj
for(int i=1;;i++) p#6tKY;N
{ +mC?.B2D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); pj Md
//Utility.log(in.readLine()); )j. .)o
sHeader=httpConnection.getHeaderFieldKey(i); *gOUpbtXa
if(sHeader!=null) bWJ&SR>
{ @a,}k<@E
if(sHeader.equals("Content-Length")) yw >Frb5p
{ m]Mm(7v(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \LM.>vJ
break; KBa0
} *d9RD~Ee
} !\!j?z=O8
else +v< \l=
break; ij?Ww'p9>
} a}X.ewg
} 0wt4C% .0
catch(IOException e){e.printStackTrace ();} OR}+)n{
catch(Exception e){e.printStackTrace ();} yB|1?L#
xqfIm%9i}
gv1y%(`|n(
Utility.log(nFileLength); Z>pZ|
8vQR'<,
Zgo%Jo
return nFileLength; k; >Vh'=X
} D"exI]
} L_Zmi$
\2CEEs'
//保存下载信息（文件指针位置） Nh\o39=
private void write_nPos() ;vy<!@Y;8
{ z0Z1J8Qq6.
try{ U$;UW3-
output = new DataOutputStream(new FileOutputStream(tmpFile)); H4$f+
output.writeInt(nStartPos.length); $W%-Mm
for(int i=0;i<nStartPos.length;i++) fk!9` p'
{ -A zOujSS
// output.writeLong(nPos); ^PUB~P/
output.writeLong(fileSplitterFetch.nStartPos); !j}L-1*{ l
output.writeLong(fileSplitterFetch.nEndPos); J|vg<[
} fXh{_>
output.close(); P3nBxw"
} )_Z^oH ]<
catch(IOException e){e.printStackTrace ();} [LO=k|&R
catch(Exception e){e.printStackTrace ();} L|B! ]}
} X4{<{D`0t8
}F"98s W
z#1"0Ks&P
//读取保存的下载信息（文件指针位置） xsiJI1/68
private void read_nPos() q@tym5
{ 1}Y3|QxF
try{ .h\Py[h<^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); O<E8,MCA[a
int nCount = input.readInt(); .(3ec/i4CF
nStartPos = new long[nCount]; g@T}h[
nEndPos = new long[nCount]; aNA]hl
for(int i=0;i<nStartPos.length;i++) 9M5W4&
{ fI1 9p Q
nStartPos = input.readLong(); >|yP`m
nEndPos = input.readLong(); sG)aw`_j
} w)B?j
input.close(); r?!:%L
} C!ch !E#
catch(IOException e){e.printStackTrace ();} o\]U;#YD
catch(Exception e){e.printStackTrace ();} *,IK4F6>:
} QZIzddwp
)(_NFpM
E AZX
private void processErrorCode(int nErrorCode) !Q*w]
{ 3zu6#3^
System.err.println("Error Code : " + nErrorCode); r7L.W
} h(<>s#=E
\P")Eh =d
L`X5\D'X
//停止文件下载 t 7o4 aBl"
public void siteStop() AI Kz]J0;
{ kkWv#,qwU
bStop = true; }WaZ+Mdg\
for(int i=0;i<nStartPos.length;i++) aKWxLe
fileSplitterFetch.splitterStop(); n:2._s T
bX,#z,
\$*CXjh3G
} r-TrA$k
} 4dcm)Xr
//负责部分文件的抓取 +L`}(yLJ)9
**FileSplitterFetch.java FO%pdLs,
*/ E #B$.K
package NetFox; dH PvVe/
J"LLj*,0"
ENIg_s4
import java.io.*; d}':7Np
import java.net.*; ES AX}uF
[DH4iG5
v_Sa0}K9
public class FileSplitterFetch extends Thread { 7C0xKF
Z,e|L4&
q,O_y<uw
String sURL; //File URL f? @Qt<+k
long nStartPos; //File Snippet Start Position BDvkY
long nEndPos; //File Snippet End Position 6V%}2YE?X
int nThreadID; //Thread's ID ^4+NPk
boolean bDownOver = false; //Downing is over D 5n\h5
boolean bStop = false; //Stop identical j1%8r*Jj
FileAccessI fileAccessI = null; //File Access interface 'z AvQm
WA~[)S0
ix2i.wdD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException gBv!E9~l
{ q+9->D(6
this.sURL = sURL; wbAwmOiZ
this.nStartPos = nStart; zGR,}v%%
this.nEndPos = nEnd; 5L[imOM0
nThreadID = id; m~AAO{\:b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Nh}-6|M
} el*|@#k}
os"R'GYmf
or3OLBf*Q
public void run() H'zAMGZa
{ Os'E7;:1h
while(nStartPos < nEndPos && !bStop) ?D _4KFr
{ d{JI] !
N=Ct3
jmwN1Se>
try{ jq%<Z,rh
URL url = new URL(sURL); +;lDU}$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @i!+Z
httpConnection.setRequestProperty("User-Agent","NetFox"); )/@KdEA:
String sProperty = "bytes="+nStartPos+"-"; #%k_V+o3
httpConnection.setRequestProperty("RANGE",sProperty); Z9$pY=8^?
Utility.log(sProperty); dxAGO(
z2YYxJc&w
IC'+{3.m8
InputStream input = httpConnection.getInputStream(); ejZ-A?f-K
//logResponseHead(httpConnection); e8("G[P>
#1E4 R}B
gi,7X\`KQ
byte[] b = new byte[1024]; -d'FKOD
int nRead; /B?wn=][
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !AE;s}v)0{
{ 8%m\J:eR
nStartPos += fileAccessI.write(b,0,nRead); j% 7Gje[
//if(nThreadID == 1) r+ 8Tp|%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X,l7>>L{g
} ^g6v#]&WA
i*N2@Z[
DSRc4|L
Utility.log("Thread " + nThreadID + " is over!"); W`9{RZ'
bDownOver = true; 7QTS@o-
//nPos = fileAccessI.write (b,0,nRead); v\6.#>NQ
} 1$03:ve1
catch(Exception e){e.printStackTrace ();} YQC.jnb2
} A"M;kzAfHM
} ~3j+hN8<
Sy <E@1
L]z8'n,
//打印回应的头信息 s3JzYDpy
public void logResponseHead(HttpURLConnection con) @JhkUGG]p
{ _VdJFjY?zc
for(int i=1;;i++) 33lh~+C
{ jm<^WQ%Cc
String header=con.getHeaderFieldKey(i); (Ud"+a
if(header!=null) [DjlkA/Zg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Zj]tiN f\"
Utility.log(header+" : "+con.getHeaderField(header)); h/\Zq
else !O!:=wq
break; 4K:Aqqhds
} {= &&J@:
} i`l;k~rP
6)YckxN^
=3'B$PY
public void splitterStop() U~yPQ8jD
{ I_8 n>\u
bStop = true; a] c03$fK
} B]yO
+pq=i
nt>3i! l
} 8~,zv_Pl
sqhIKw@
!U4YA1>>
/* aj1g9y
**FileAccess.java uYlyU~M:D
*//文件访问(定位，写) Jb> X$|N'%
package NetFox; /<T{g0s
import java.io.*; ?Mo)&,__
\25EI]
VgbT/v
public class FileAccessI implements Serializable{ GKWsJO5 n
~FAk4z=Ed
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `j'1V1
RandomAccessFile oSavedFile; 3dZj<(.
long nPos; R!"`Po
% mPv1$FH
[C-FJ>=S
public FileAccessI() throws IOException ^ux'-/
{ be-HF;lZe'
this("",0); UnVa`@P^:G
} ;=P!fvHk
dhP")@3K;p
fbdpDVmpU
public FileAccessI(String sName,long nPos) throws IOException O`_, _
{ #t Pc<p6m
oSavedFile = new RandomAccessFile(sName,"rw"); W"\`UzOLQ
this.nPos = nPos; ryzNM3
oSavedFile.seek(nPos); Ht}?=ZzW
} /ioBc}]
b O}&i3.L;
/9SoVU8
public synchronized int write(byte[] b,int nStart,int nLen) 7NOF^/nU
{ uTO%O}D N
int n = -1; !w/fwOo
try{ EcytNYn
oSavedFile.write(b,nStart,nLen); -~J5aG[@~>
n = nLen; @|w/`!}9q
} B )\;Ja
catch(IOException e) 7z\#"~(.
{ ]d{lS&PRlg
e.printStackTrace (); ON>l%Ae4G
} hH05p!2
3H>\hZ
iN0'/)ar
return n; b ettOg
} BSr#;;\
LV$Ko_9eA
5TeGdfu @
} ei}(jlQp
muK.x7zyl
)L":I
/* 5D7k[+6
**SiteInfoBean.java 77+3CME{'
*/ m9c`"!
package NetFox; ;/ |tU o$
c;a<nTLn
ESFJN}Q%0.
public class SiteInfoBean { Ui1s]R
s`v$r,N0
#tw_`yh
private String sSiteURL; //Site's URL m' |wlI[lq
private String sFilePath; //Saved File's Path kPAg*
private String sFileName; //Saved File's Name O^ &m
private int nSplitter; //Count of Splited Downloading File G%!i="/9
>xF&>SDC
"HH<5M
public SiteInfoBean() 6u`$a&dR'l
{//nSplitter的缺省值为5 Qk|+Gj
//default value of nSplitter is 5 7GErh,
this("","","",5); a>d`g
} CQ{{J{pU"
3U!=R-
*L Y6hph"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) tt6GtYrC 1
{ \W=Z`w3
sSiteURL= sURL; FKhgUnw
sFilePath = sPath; #3RElI
sFileName = sName; ug"4P.wI
this.nSplitter = nSpiltter; X1[zkb
t0/Ol'kgs
>r}?v3QW
} c@nh>G:y{&
0pH$MkQ
ZnuRy:
public String getSSiteURL() tWaGCxaE
{ 0G Q8}r
return sSiteURL; Ul 85-p
} 6o(.zk`d
<*/Z>Z_c2
qwn EVjf
public void setSSiteURL(String value) B T {cTj0W
{ q@wX=
sSiteURL = value; Imclz4'8
} RjrQDh|((
8|L5nQ
O9ro{ k
public String getSFilePath() z 9WeOs
{ R,OT\FQ<
return sFilePath; &wu1Zz[qcz
} p=i6~
:w4N*lV-
55Mtjqfp
public void setSFilePath(String value) z-sq9Qp&x
{ G$CSZrP.
sFilePath = value; E4.A$/s8[
} MFWkJbZV
*{p:C
]xJ.OUJy
public String getSFileName() <'hoN/g
{ D})12qB;u9
return sFileName; OKu~Nb*
} EW`WFBjj
j*GS')Cm
W58%Zz4a
public void setSFileName(String value) mW,b#'hy
{ 3mg:9]X9
sFileName = value; *Z2Ko5&Y2
} [W3sveqj&
GI:!,9
N+pCC
public int getNSplitter() ) <w`:wD
{ N6%L4v8-}X
return nSplitter; [l<&eI&ln
} *Aug7 HlS
X_,R!$wbg:
qHd7C3
public void setNSplitter(int nCount) #hXvGon$?
{ W}%[i+
nSplitter = nCount; G)o:R iq
} {/48n83n
} r-]%R:U*
n(SeJk%>9
Fp]ErDan
/* 2{oQ
**Utility.java (eHTXk*V`
*/ t2m7Yh5B
package NetFox; qc';<
X7tBpyi
Q=#FvsF#z3
public class Utility { >>8{N)c5E
,,ML^ey
)gAqWbkB
public Utility() QDKY7"H
{ y!q`o$nK
GSfU*@L3
f<'D?d)L^
} {)Shc;Qh
^U,Dx
//线程睡眠 <$K7f
public static void sleep(int nSecond) ]A1'+!1$
{ e]{=#
try{ \#F>R,
Thread.sleep(nSecond); PM&NY8|Zy
} Zv8_<>e
catch(Exception e) Wo,93]
{ :H:+XIgoR
e.printStackTrace (); GBT219Z@8
} \vS >jB
} 2|NQ5OA0
/R>YDout}
//日志 6#a82_
public static void log(String sMsg) ]M~7L[
{ VAe[x `
System.err.println(sMsg); Id8e%)
} <KE%|6oER
Fw#1?/K~
Xc~BHEp
public static void log(int sMsg) i8f+woZL
{ %:OX^^i;
System.err.println(sMsg); SQMtR2
} b%0@nu4
} XQtV$Lw
vV"I}L
+HgyM0LFg
/* 0vMKyT3 c
**TestMethod.java Mh{;1$j#
*/ D@]/%;
package NetFox; \c!e_rZ
RS@G.|
aadw#90
public class TestMethod { cxx8I
@3~Wukc
TKVS%//
public TestMethod() Q:'r p
{ ///xx/weblogic60b2_win.exe }?HWUAL\
try{ A.RG8"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8>xd
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CdtCxy5
SiteFileFetch fileFetch = new SiteFileFetch(bean); `B$Pk0>5r
fileFetch.start(); 0oqOX
} 0WyOORuK
catch(Exception e){e.printStackTrace ();} =-qYp0sVP
h<n2pz}
_94R8?\_V7
} 8Au W>7_
_SH~.Mt_!
-"XHN=H
public static void main(String[] args) m/< @Qw
{ @4Q/J$
new TestMethod(); z(#dL>d$'
} $bN_0s0:'
} l%qh^0
点击下载更多相关资料