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)); &YP#M|
} USJ-e
for(int i=0;i<nEndPos.length-1;i++) DbX{#4lx
{ lkIn%=Z
nEndPos = nStartPos[i+1]; z5\;OLJS,
} -php6$|
nEndPos[nEndPos.length-1] = nFileLength; Ths_CKwgWY
} D,l,`jv*
} %9C@ Xl
B=L&bx
E&$_`m;
//启动子线程 v'2[[u{7*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4\t1mocCSN
for(int i=0;i<nStartPos.length;i++) FaTa(3$%
{ =%)+%[wv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G>qZxy`c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ".*x!l0y7
nStartPos,nEndPos,i); co4h*?q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 59uwB('|lH
fileSplitterFetch.start(); Y>."3*^
} :S@1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w^k;D,h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }]1BO
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8cx=#Me
nEndPos = " + nFileLength); 89}Y5#W
// fileSplitterFetch[nPos.length-1].start(); gE/Tj$
',7??Q7j&v
?VU(Pq*`
//等待子线程结束 oj,lz?
//int count = 0; u#7+U\
//是否结束while循环 Q~D`cc|]
boolean breakWhile = false; vY|^/[x#B
z(uZF3
MjfFf} @
while(!bStop) \/7i-B]G7
{ oz'\q0
write_nPos(); Ey{%XR+*;
Utility.sleep(500); FxG7Pk+=
breakWhile = true; jdeV|H} u
stl 1QO(h
c47")2/yO
for(int i=0;i<nStartPos.length;i++) `pZs T ^G[
{ %wV>0gQTf
if(!fileSplitterFetch.bDownOver) }H4=HDO
{ G}@#u9
breakWhile = false; j Ib
break; DH DZ_t:
} x Ha=3n
} !%<^K.wG
if(breakWhile) kU5.iK'
break; EY`H}S!xy
g_*T?;!.U
8?t"C_>*e
//count++; /NT[ETMk+
//if(count>4) XALI<ZY
// siteStop(); *MNHT`Y^o
} a>4uiFiv
(fD ;g9
'J*<iA*W
System.err.println("文件下载结束！"); BIaDY<j90
} h.rD}N\L
catch(Exception e){e.printStackTrace ();} ~sQjl]
} ?zJpD8e
/5AW?2)
C`rLj5E%
//获得文件长度 e)nimq {6
public long getFileSize() *x~xWg9^
{ 1RLY $M
int nFileLength = -1; WlB'YL-`g
try{ (LvS :?T}
URL url = new URL(siteInfoBean.getSSiteURL()); $ZPX]2D4B#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2s*#u<I
httpConnection.setRequestProperty("User-Agent","NetFox"); ~pk(L[G
HWns.[
V=I"-k}RL
int responseCode=httpConnection.getResponseCode(); HC {XX>F^
if(responseCode>=400) +^aFs S
{ $VG*q
processErrorCode(responseCode); B(k=oXDF
return -2; //-2 represent access is error wmNHT _
} Yw3oJf&
wo2@hav
`i,_aFB|
String sHeader; $FH18
zxb/
i[C~5}%
for(int i=1;;i++) 'PZ|:9FX!
{ 6q<YJ.,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yAT^VRbv
//Utility.log(in.readLine()); {s?M*_{|
sHeader=httpConnection.getHeaderFieldKey(i); 14eW4~Mr
if(sHeader!=null) os3 8u!3-
{ CDj~;$[B
if(sHeader.equals("Content-Length")) )'4P.>!!aQ
{ rsn.4P=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (w(
break; %U7.7dSOI;
} -b&{+= ^c
} v7
else }/dRU${!
break; ubsSa}$q
} #BVtL :x@
} I:&/`K4,x,
catch(IOException e){e.printStackTrace ();} snM Z0W
catch(Exception e){e.printStackTrace ();} aIy*pmpD=
@K223?c8l
[$(%dV6O
Utility.log(nFileLength); h-a!q7]l
rj]F87"
Z0!5d<
return nFileLength; L(S'6z~_9
} z2gk[zY&
Zv]x'3J#Y
<>xJn{f0c
//保存下载信息（文件指针位置） -Lu)'+
private void write_nPos() %m,6}yt
{ ha@L94Lq
try{ @tohNO>
output = new DataOutputStream(new FileOutputStream(tmpFile)); "|Fy+'5}
output.writeInt(nStartPos.length); 0Q,g7K<d
for(int i=0;i<nStartPos.length;i++) }uHrto3M
{ iF5'ygR-Z
// output.writeLong(nPos); c:S] R"
output.writeLong(fileSplitterFetch.nStartPos); W+wA_s2&D
output.writeLong(fileSplitterFetch.nEndPos); zQ?!f#f
} k-V,~c
output.close(); ~9^)wCM+
} <P ,~eX(r
catch(IOException e){e.printStackTrace ();} @[<nQZw:
catch(Exception e){e.printStackTrace ();} s..lK "b
} [u@Jc,
Z 2}ah
Ft=zzoVKg
//读取保存的下载信息（文件指针位置） 'crlA~&#/
private void read_nPos() c5q9LQ/
{ "]'?a$\ky:
try{ yw[#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0C<[9Dl.G8
int nCount = input.readInt(); >FjR9B
nStartPos = new long[nCount]; 7qOa ;^T
nEndPos = new long[nCount]; exh/CK4;
for(int i=0;i<nStartPos.length;i++) |Z\R*b"
{ X)SDG#&+bF
nStartPos = input.readLong(); 3P~o"a>
nEndPos = input.readLong(); j1?j6s
} (@X~VACT
input.close(); Wc3kO'J
} fy@avo9
catch(IOException e){e.printStackTrace ();} H>Q%"|
catch(Exception e){e.printStackTrace ();} &*G<a3Q
} j.~!dh$mg
]$afC!Z
G CRz<)1
private void processErrorCode(int nErrorCode) -U~
{ 2Y}?P+:%>
System.err.println("Error Code : " + nErrorCode); h'J|K^na
} !f>d_RG
rrg96WD
$p!yhn7
//停止文件下载 xX3'bsN
public void siteStop() I{JU-Jk|
{ dpQG[vXe
bStop = true; bn 6WjJ~Z+
for(int i=0;i<nStartPos.length;i++) J{[n?/A{
fileSplitterFetch.splitterStop(); DU%w1+u
1}hIW":3Sr
4v p
} ~/NKw:
} A,su;Qh
//负责部分文件的抓取 i'd2[A.7I
**FileSplitterFetch.java ,h|qi[7
*/ f~E*Zz`;
package NetFox; Vc^HVyAx@n
$VAx:Y|
jR=s#Xz
import java.io.*; !$2Z-!
import java.net.*; $'W}aER
fA'qd.{f^
ly% F."v
public class FileSplitterFetch extends Thread { JvYPC
!8 &=y
T5urZq*R
String sURL; //File URL 86@c't@
long nStartPos; //File Snippet Start Position 3mPjpm
long nEndPos; //File Snippet End Position )9,
int nThreadID; //Thread's ID ys_`e
boolean bDownOver = false; //Downing is over B1]bRxwn?
boolean bStop = false; //Stop identical FZreP.2)!
FileAccessI fileAccessI = null; //File Access interface vVGDDDz/
_%'},Xd.z
Cs2;z:O]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?!qY,9lhH
{ Uax+dl
this.sURL = sURL; fEB7j-t
this.nStartPos = nStart; (E,T#uc{
this.nEndPos = nEnd; Vcd.mE(t%
nThreadID = id; $/Aj1j`"9+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 hF2IW{=!
} dEBcfya
2VW}9O
.CP&bJP%
public void run() s {^yj
{ Zmbfq8K
while(nStartPos < nEndPos && !bStop) dr4Z5mw"E
{ I ZQHu h
No2b"G@
t1E[uu,V8
try{ 6c0>gUQx-
URL url = new URL(sURL); CJ}5T]WZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @FdSFQ/9
httpConnection.setRequestProperty("User-Agent","NetFox"); #plY\0E@
String sProperty = "bytes="+nStartPos+"-"; 4Llo`K4
httpConnection.setRequestProperty("RANGE",sProperty); L(GjZAP
Utility.log(sProperty); <dyewy*.L
=4d (b ;
R_=6GZH$G
InputStream input = httpConnection.getInputStream(); zB yqD$
//logResponseHead(httpConnection); -i-?.:
Z{'i F
@F(mi1QO
byte[] b = new byte[1024]; X.`~>`8
int nRead; !3T&4t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) x@8a''
{ KZ~*Nz+H2
nStartPos += fileAccessI.write(b,0,nRead); R$zH]
//if(nThreadID == 1) f6$b s+oP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q -8t'7
} 3Hf0MAt
iR"N13
;c$J=h]
Utility.log("Thread " + nThreadID + " is over!"); G:g69=x y
bDownOver = true; O|_h_I-2
//nPos = fileAccessI.write (b,0,nRead); C]Q8:6b
} QeF3qXI
catch(Exception e){e.printStackTrace ();} FVhU^
} .F+@B\A<
} DBP9{ x$
8QMPY[{
!ct4;.2 D
//打印回应的头信息 I-OJVZ( V
public void logResponseHead(HttpURLConnection con) a22XDes=
{ q+,Q<2J
for(int i=1;;i++) Jmx Ko+-
{ ws4cF N9P?
String header=con.getHeaderFieldKey(i); f 2l{^E#h
if(header!=null) W456!OHa
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [$[:"N_
Utility.log(header+" : "+con.getHeaderField(header)); *hcYGLx r
else cu+FM
break; [z7bixN
} K_&4D'
} QY== GfHt
#:SNHM^><
4`,j=3
public void splitterStop() Dc)dE2
{ s.8{5jVG
bStop = true; :6%Z]tt
} B7imV@<
s&j-\bOic9
=hl}.p
} v$^Z6>vVI
gCyW Vp
{T].]7Z
/* D= 7c(
**FileAccess.java >t7x>_~
*//文件访问(定位，写) $tl\UH7%2
package NetFox; '(/7[tJ
import java.io.*; yr,=.?C-
{s;U~!3aY
Jec'`,Y
public class FileAccessI implements Serializable{ H= X|h)
p)+k=b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ZRYEqSm
RandomAccessFile oSavedFile; n'emNRa
long nPos; 0V?F'<qy
8g7<KKw
-44&#l^}_u
public FileAccessI() throws IOException =JmT:enV
{ {p,]oOq\
this("",0); NF? vg/{
} CD8}I85K
mx=BD'
vhhC> 7
public FileAccessI(String sName,long nPos) throws IOException U,LTVYrO
{ %Rsp;1Z
oSavedFile = new RandomAccessFile(sName,"rw"); Sf8{h|71
this.nPos = nPos; b".L_Ma1*
oSavedFile.seek(nPos); }1rm
} Ps<d('=
B/n[m@O
?R$&Xe!5
public synchronized int write(byte[] b,int nStart,int nLen) p'om-
{ +zs4a96[
int n = -1; 5scEc,JCi
try{ =Qn ;_+Ct
oSavedFile.write(b,nStart,nLen); $.bBFWk
n = nLen; 9H%X2#:fH
} (P`3 @H
catch(IOException e) F;>!&[h}G
{ 'PP#^aI,
e.printStackTrace (); ^4o;$u4R
} R=KQ
vI@%Fg+D
wiBVuj#
return n; Ox@P6|m
} *2GEnAZb7n
J4\qEO
h5K$mA5
} y.q(vzg\_
x+]\1p
s8h-,@p
/* )K2HK&t:
**SiteInfoBean.java & j+oJasI
*/ M8TSt\
package NetFox; -neKuj
95V@X ^Ee
Zcc9e03
public class SiteInfoBean { `Ry]y"K
LupkrxV
]EpWSs!"g
private String sSiteURL; //Site's URL x|5k<CiA
private String sFilePath; //Saved File's Path b4pm_Um
private String sFileName; //Saved File's Name =ha{Ziryo
private int nSplitter; //Count of Splited Downloading File &:7ZQ1
3=L.uXVb
Ft!],n-n*
public SiteInfoBean() RZCq{|L
{//nSplitter的缺省值为5 71{p+3Z&
//default value of nSplitter is 5 k|!EDze43?
this("","","",5); nt@aYXK4|
} T|TO}_x
+="e]Yh;
|u;v27
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qQH]`#P
{ @qHNE,K
sSiteURL= sURL; 6!(@@^7{*
sFilePath = sPath; Q0ON9gqqv
sFileName = sName; \0gM o&
this.nSplitter = nSpiltter; (zFi$
k Zq!&
&EnuE0BD
} ^) s2$A:L
NW&b&o
\(vY%DL1:
public String getSSiteURL() ]S5JUAGkE*
{ y?q*WUh
return sSiteURL; $81*^
} )d>!"JB-
L:'J Bhg
5hy""i
public void setSSiteURL(String value) J`^I./
{ oo.2Dn6z
sSiteURL = value; }O4^Cc6
} q')R4=0 K
fP `b>]N_
1N>|yQz
public String getSFilePath() aUtnR<6
{ uF3qD|I\
return sFilePath; t0T"@t#c
} m RO~aD!N
x a06i#
QD>"]ap,o
public void setSFilePath(String value) <|Pun8j
{ ez6EjUk
sFilePath = value; q+vx_4
} I=NZokfS
xcf%KXJf6
oGRhnP'PF+
public String getSFileName() M )2`+/4
{ x HhN
return sFileName; ;{%\9nS
} {b
4BKI-;v$
\<)9?M :
public void setSFileName(String value) 4zo5}L`Y
{ %V ;?
sFileName = value; M%0C_=zg
} JQ@E>o7_
[YcG(^^
McQe1
public int getNSplitter() *NClfkZ
{ 9& 83n(m
return nSplitter; GJqJlgHe
} Pw61_ZZ4B\
@>U-t{W
KSNPkd6
public void setNSplitter(int nCount) N D2L_!g:(
{ H?X|(r|+
nSplitter = nCount; TBT:/Vfun
} ={xE!"
} 7!JQB
WV_.Tiy<
*N<&GH(j
/* y;o^- O
**Utility.java &Ob!4+v/GP
*/ $ . 9V&
package NetFox; >\Ww;1yV
O6G0
:HwA 5Z#
public class Utility { [+DW >Et
<U\B!fO'
gY8>6'~mS
public Utility() A"rfZ`
{ LpqO{#ZG
l|k`YC x
z\%Ls
} _c_[C*T]
x}8yXE"
//线程睡眠 L|}lccpI
public static void sleep(int nSecond) \hEN4V[
{ ]n~ilS.rkl
try{ ~"kb7Fxp
Thread.sleep(nSecond); Ot6aRk
} pv Gf\pu
catch(Exception e) +y3%3EKs1~
{ suzZdkMA
e.printStackTrace (); 65aK2MS@
} !74S
} W|g4z7Pb
7M<'/s
//日志 8Hn|cf0
public static void log(String sMsg) #kaY0M
{ @dPTk"P
System.err.println(sMsg); y3o25}"
} io{@^1ab
Qh'ATo
6U R2IxbE
public static void log(int sMsg) [c|]f_ZdK
{ &bfA.& `
System.err.println(sMsg); &-B^~M*??
} Nbi.\
} k@3Q|na
283F)T\Rv
Z*= $8e@
/* x?2@9u8Yb
**TestMethod.java R&BTA
*/ L'0B$6
package NetFox; OZ~5*v
yU-e3O7L
sWc*5Rt
public class TestMethod { \Yc'~2n
0,89H4
V#S9H!hm$
public TestMethod() \(^nSy&N
{ ///xx/weblogic60b2_win.exe 5a|w+HO,
try{ z;|A(*Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r[b(I@T+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <?riU\-]y
SiteFileFetch fileFetch = new SiteFileFetch(bean); ='s(|
fileFetch.start(); F.=2u"[*&
} C8V/UbA /
catch(Exception e){e.printStackTrace ();} BlA_.]Sg$
xgKdMW'%g:
'z%o16F)L
} xQ^E"Q,1
noml8o
V`XNDNJ:
public static void main(String[] args) K,:cJ
{ ECrex>zr%
new TestMethod(); uP~@U"!
} Vt".%d/`7
} 2[O&NdP\Zk
点击下载更多相关资料