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)); qQv?J]l
} =rFgOdj
for(int i=0;i<nEndPos.length-1;i++) 3FR'N%+
{ <sE0426 {
nEndPos = nStartPos[i+1]; @.6l^"L
} t ]7>' U
nEndPos[nEndPos.length-1] = nFileLength; sFqZ@t}~
} `9SuDuw;s
} -Xb]=Yf-
< {$zOF}
l1fP@|
//启动子线程 `D6Bw=7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p(fYpD
for(int i=0;i<nStartPos.length;i++) S;[9 hI+
{ dq?{?~3
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T.]+T[}!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #p_3j 0S
nStartPos,nEndPos,i); 4{7O}f
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pfj{TT.#L
fileSplitterFetch.start(); CA, &R<]
} pn<M`,F~q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x >hnH{~w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ep* (
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %}t.+z(S
nEndPos = " + nFileLength); dcew`$SJp
// fileSplitterFetch[nPos.length-1].start(); -$yNJ5F`
8wKF.+_A
gpB3\
//等待子线程结束 Q&S\?cKe
//int count = 0; ]-FK6jw
//是否结束while循环 j?K]0j;
boolean breakWhile = false; ]~iOO %&R
f^z/s6I0
S4508l
while(!bStop) YtI2Vr/9
{ _1S^A0ft
write_nPos(); O RAKg.49
Utility.sleep(500); @=B'<&g$Xv
breakWhile = true; Rrmk\7/
LT']3w
l( /yaZ`
for(int i=0;i<nStartPos.length;i++) ^dj avJ
{ O+~.p
if(!fileSplitterFetch.bDownOver) eAR]~ NiW
{ ,g\%P5
breakWhile = false; D^V0kC p!F
break; ,R_ KLd
} xFvDKW)_X7
} 7m3|2Qv
if(breakWhile) ?4vf2n@
break; d#6'dKV$
:\[W]
5RD\XgyN]
//count++; Exd$v"s Y
//if(count>4) 6fV%[.RR
// siteStop(); sJu^deX
} Ad!= *n
Yz4)Q1
@LZ'Qc }@
System.err.println("文件下载结束！"); %GG:F^X#
} t ' _Au8
catch(Exception e){e.printStackTrace ();} $J}d6%
} @y?<Kv}s
&0! f_
(T+fO}0
//获得文件长度 wn2+4> |~p
public long getFileSize() xrb %-vT
{ -v"\WmcS
int nFileLength = -1; F/GfEMSE
try{ /;>U0~K
URL url = new URL(siteInfoBean.getSSiteURL()); K8xwPoRL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G&8)5d[
httpConnection.setRequestProperty("User-Agent","NetFox"); {nTQc2T?;
Uv|z c
VQA}!p
int responseCode=httpConnection.getResponseCode(); k/[*Wz$W
if(responseCode>=400) "#Ov!t
{ rS1mBrqD
processErrorCode(responseCode); T*YbmI]4
return -2; //-2 represent access is error c4Q{
} AfAg#75q
3>LyEXOW
U^+xCX<
String sHeader; wc@X:${
.PjJ g^^
P5 fp!YF
for(int i=1;;i++) ?M?S+@(
{ "A\.`*6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .u[hK
//Utility.log(in.readLine()); e_mUO"
sHeader=httpConnection.getHeaderFieldKey(i); 7u8HcHl
if(sHeader!=null) rw>X JE
{ IO/%X;Y_
if(sHeader.equals("Content-Length")) 9gFb=&1k
{ pdCn98}%-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &%3$zgvR
break; Fl)p^uUtl
} f%r0K6p
} [>+}2-#
else pZ4]KxX@
break; ' *hy!f]
} i"|="O0v5
} l"9.zPvT<
catch(IOException e){e.printStackTrace ();} qbu>YTj
catch(Exception e){e.printStackTrace ();} S-)mv'Al'F
[X>\!mt
$@]tTz;b
Utility.log(nFileLength); _m3}0q
ch2Qk8
H(f~B<7q
return nFileLength; rzmd`)g
} (pY'v/a-
FtBYPSGz
"{a-I=s\C
//保存下载信息（文件指针位置） Vy*&po[
private void write_nPos() X;$g7A
{ 0}'
try{ <?|v-(E
output = new DataOutputStream(new FileOutputStream(tmpFile)); -"*UICd
output.writeInt(nStartPos.length); YbS$D
for(int i=0;i<nStartPos.length;i++) r0 %WGMk2
{ A4!IbJD,0
// output.writeLong(nPos); ^H]q[XFR
output.writeLong(fileSplitterFetch.nStartPos); :5kgJu
output.writeLong(fileSplitterFetch.nEndPos); }9Yd[`
} QP+zGXd}(
output.close(); G55-{y9Q
} B_;W!
catch(IOException e){e.printStackTrace ();} FFE IsB"9
catch(Exception e){e.printStackTrace ();} fAx7_}k/ m
} -9Iz$(>a
I_vPGafMx
;Y:_}kN8_
//读取保存的下载信息（文件指针位置） c,WRgXL
private void read_nPos() P}=u8(u
{ ]7H ?
try{ $|0_[~0-n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;^QG>OP$
int nCount = input.readInt(); &{#4^.Q
nStartPos = new long[nCount]; bcgh}D
nEndPos = new long[nCount]; OC)~psQK
for(int i=0;i<nStartPos.length;i++) "6.JpUf
{ PbR6>'
nStartPos = input.readLong(); _Ju@<V$
nEndPos = input.readLong(); UdBP2lGd
} \9[_*
input.close(); hVvPI1[2
} H)XHlO^
catch(IOException e){e.printStackTrace ();} 45cMG~]p
catch(Exception e){e.printStackTrace ();} f<!3vAh
} jVh I`F{n
{/f\lS.5g
FmU>q)
private void processErrorCode(int nErrorCode) *Q=3v
{ iTb k]$
System.err.println("Error Code : " + nErrorCode); 8<z]rLQw?%
} }(}+I}&~
zj G>=2
IfyyA
//停止文件下载 <@;Y.76~
public void siteStop() Rg/*)SKj
{ -b1VY4m-
bStop = true; 6.]x@=Wm
for(int i=0;i<nStartPos.length;i++) kbij Zj{
fileSplitterFetch.splitterStop(); `1I@tz|
3hzI6otKS
Q/e$Ttt4J
} OKDBzl
} ts2;?`~
//负责部分文件的抓取 &r0b~RwUv
**FileSplitterFetch.java [/.5{|&GSt
*/ iUcDj:
package NetFox; FScE3~R
Q4YIKNN|7
OG\TrW-ug
import java.io.*; vIk;x
import java.net.*; UNc!6Q-.
vfW
P%Fkd3e+
public class FileSplitterFetch extends Thread { o)NQE?
V?{[IMRC
-49z.(@ki
String sURL; //File URL J{98x zb
long nStartPos; //File Snippet Start Position =F>@z4[P-
long nEndPos; //File Snippet End Position MGUzvSf
int nThreadID; //Thread's ID 7 S^iGe
boolean bDownOver = false; //Downing is over +-=o16*{ !
boolean bStop = false; //Stop identical p h[ ^ve
FileAccessI fileAccessI = null; //File Access interface 3U#z {%
\/8 I6a=
9v7l@2/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *G{%]\s?
{ ?t LJe
this.sURL = sURL; h> K~<BAz'
this.nStartPos = nStart; IvLo&6swW
this.nEndPos = nEnd; -Fcg}\9
nThreadID = id; }F=+*-SYZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a<CN2e_Z
} &@E{0ZD
fJ!i%</V
d8 1u
public void run() x"kc:F
{ uo`O$k<;
while(nStartPos < nEndPos && !bStop) Mx,QgYSu
{ }t4?*:\
fFG, ^;7-O
`N0Mm7
try{ 'n>,+,&
URL url = new URL(sURL); L4th 7#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]fH U/%
httpConnection.setRequestProperty("User-Agent","NetFox"); "*o54z5"
String sProperty = "bytes="+nStartPos+"-"; y(M-
httpConnection.setRequestProperty("RANGE",sProperty); e/@tU'$
Utility.log(sProperty); ~GL"s6C$`;
&V;^xMO!
8nOMyNpy~M
InputStream input = httpConnection.getInputStream(); ,Y~{RgG
//logResponseHead(httpConnection); |%JJ S^)
5@3[t`n'
#BQ7rF7CNE
byte[] b = new byte[1024]; +dWx?$n
int nRead; K\5'pp1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) : `D[0
{ m&)5QX
nStartPos += fileAccessI.write(b,0,nRead); L(tA~Z"k
//if(nThreadID == 1) !;'.mMO&%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r&AX
} =2HR+
odxsF(Q0p
M{Ss?G4H
Utility.log("Thread " + nThreadID + " is over!"); (yk^%
bDownOver = true; 7.4Q
//nPos = fileAccessI.write (b,0,nRead); x\ieWF1
} O[O`4de9
catch(Exception e){e.printStackTrace ();} 9W$d'IA
} +QNFu){G
} $~UQKv>
Tjo K]]
}V.Wp6"S
//打印回应的头信息 -^=sxi,V
public void logResponseHead(HttpURLConnection con) b&.j>=
{ 4am`X1YV#
for(int i=1;;i++) ]^,<Ez
{ rM6^pzxe
String header=con.getHeaderFieldKey(i); (g2?&b iuz
if(header!=null) K5U=%z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $x&@!/&|pv
Utility.log(header+" : "+con.getHeaderField(header)); *@'4 A :A
else /H+br_D9
break; b#p)bcz!I
} BXgAohg!
} /E'cy
h?wNmLre
]=v_u9;
public void splitterStop() mx@F^
{ y=y=W5#;77
bStop = true; ;Ab`b1B
} *ayn<Vlh`^
mQt';|X@
%1ofu,%
} h4CDZ
}>vf(9sF`
)/FB73!
/* +(/?$dRH
**FileAccess.java Vx_lI #3
*//文件访问(定位，写) U~z`u&/
package NetFox; 0-~Y[X"9.
import java.io.*; /3D!,V,
#yZZ$XOk
u9>zC QRO
public class FileAccessI implements Serializable{ iTgGf
-|^}~yOx0=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b#0y-bR
RandomAccessFile oSavedFile; j`I[M6Qxh
long nPos; LjUBV_J
5Cxh>,k
"Y@rNmBj
public FileAccessI() throws IOException &Im{p7gf!b
{ ")|3ZB7>*
this("",0); m7X&"0X
} +}c '4hRv
4,L(
IVD1mk
public FileAccessI(String sName,long nPos) throws IOException Q!/<=95E
{ xlVQ[Mt
oSavedFile = new RandomAccessFile(sName,"rw"); Eq-fR~<9
this.nPos = nPos; ia15r\4j)
oSavedFile.seek(nPos); lyiBRMiP|
} 4fBgmL
.J' 8d"+
4?XX_=+F|
public synchronized int write(byte[] b,int nStart,int nLen) c^P8)gPf
{ _[8xq:G
int n = -1; !}wJ+R ^2
try{ "sF&WuW|
oSavedFile.write(b,nStart,nLen); \KfngYD]W
n = nLen; "pq#A*
} Saa#Mj`M
catch(IOException e) PT4Xr=z =
{ rP.qCl+J
e.printStackTrace (); <tK6+isc
} CBx1.xL
H=]$9ZH!
>nmby|XtW
return n; E",s]
} 5)4*J.
*leQd^47
4s/4z@3a
} ^ ab%Mbb
u`Djle
VKy:e.
/* ";B.^pBv@;
**SiteInfoBean.java 6N(Wv0b $
*/ {snLiCl
package NetFox; #M*h)/d[A
f XxdOn.
sKIWr{D
public class SiteInfoBean { b?7?iV4
uy\<t
T/G1v;]
private String sSiteURL; //Site's URL Mj |)KDL
private String sFilePath; //Saved File's Path Ixm<wKwW#
private String sFileName; //Saved File's Name {:40Jf
private int nSplitter; //Count of Splited Downloading File qF=D,Dlz
P8!Vcy938
CYrVP%xRA
public SiteInfoBean() `L`*jA+_
{//nSplitter的缺省值为5 '5wa"/ ?w
//default value of nSplitter is 5 <lZyUd
this("","","",5); AbUPJF"F
} >FPE%X0+
|Q:$G!/
qgrRH'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I_.(&hMn
{ `Bx3grZ 7&
sSiteURL= sURL; QQPbKok>
sFilePath = sPath; !%J;dOcU
sFileName = sName; SQ5SvYH
this.nSplitter = nSpiltter; fI[tU(x
YIb5jK`
*%(8z~(\
} v=nq P{
]]@jvU_?kS
])}{GW
public String getSSiteURL() 9'3%%o
{ w[\*\'Vm0
return sSiteURL; wl^bvHG
} t ),~w,7(J
&Wfs6g
<&TAN L
public void setSSiteURL(String value) iZ#dS}VlJ
{ Zoj.F
sSiteURL = value; :gDIGBK,
} 0trVmWQ8
*#e%3N05_
vn3<LQ]
public String getSFilePath() '#xxjhF^
{ Rct|"k_"Ys
return sFilePath; r~F T,
} ,WA7Kp9
1"A1bK
3sc5meSu'
public void setSFilePath(String value) G40,KCa
{ ;YNN)P%"
sFilePath = value; \c>9f"jS_
} eS fT+UL
C$oY,A,
ZgF-.(GV
public String getSFileName() _1hc^j
{ 9>u2; 'Ls
return sFileName; &#v^y3r
} SSycQ4[{o
} IFZ$Y
xy46].x-
public void setSFileName(String value) wx -NUTRim
{ 67%eAS
sFileName = value; Mcc774'*9
} jVL<7@_*
^"v~hjM#
UevbLt1Y
public int getNSplitter() J|_&3@r
{ ^M6v;8EU
return nSplitter; [ik D4p=
} ?l`DkUo*j
Tk$rwTCl
!I]fNTv<
public void setNSplitter(int nCount) 'VFxg,
{ *CA|}l
nSplitter = nCount; o,9E~Q'`{
} u /JEQz1
} ESiNW&u2
|;'V":yDs
YNc%[S[u^1
/* }Xyu"P
**Utility.java w7p%6m
*/ XV1#/@H;
package NetFox; y;Q_8|,F
r!V#@Md
U`K5 DZ~
public class Utility { I!9u](\0
]0by6hQ
cf1Ve\(YGI
public Utility() 'Kxs>/y3
{ -en:81a#
WqqrfzlM
OJ8W'"`L&
} v3[Z]+ ]
gg'lb{oG
//线程睡眠 9X,dV7 yW
public static void sleep(int nSecond) Y oNg3
{ 8U0y86q>)E
try{ iU9de
Thread.sleep(nSecond); OgyETSN8C
} R!W!8rr3
catch(Exception e) gSEj/?
{ 0`"]mYH
e.printStackTrace (); 6g8{;6x
} jIK*psaV
} YKf,vHau
T({:Y. A;
//日志 /u!I2DF
public static void log(String sMsg) 8NudY3cU!
{ _ot4HmD
System.err.println(sMsg); h|yv*1/|
} LT!B]y
qWKpnofa
v~q2D"
public static void log(int sMsg) {,*G}/9<
{ ;nji<
System.err.println(sMsg); !EF~I8d\]
} -Vn9YeH+
} c?CwxI_b8
gZ
x%B^hH;W
/* ~Lhq7;=H?O
**TestMethod.java ~l}rYi>g%
*/ dl'pl
package NetFox; e{:P!r aM
d,iW#,
( Z\OqG
public class TestMethod { !Y!Cv %
@JT9utct
5(1Zj`>'
public TestMethod() Ul^/Dh
{ ///xx/weblogic60b2_win.exe Z*.fSmT8)
try{ +Qt=N6>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {CR~G2Z
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); BZQ98"Fz*
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,G e7 9(
fileFetch.start(); C 6Bh[:V&
} 2uZ <q?=
catch(Exception e){e.printStackTrace ();} :1q+[T/ @
A1{P"p!
-_ .f&l8
} %h g=@7,|
~1`.iA
SOE#@{IXBa
public static void main(String[] args) a)MjX<y
{ )W:`Q&/G
new TestMethod(); YM 0f_G=
} ?Vb=W)Es
} 1}tZ,w>
点击下载更多相关资料